The pH of pure water at 50°C is approximately e) 7.00.
The autoionization constant of water is given by the expression:
Kw = [H+][OH-]
At 50°C, Kw = \(5.5 x 10^-14.\) Since pure water has equal concentrations of H+ and OH- ions, we can write:
[H+] = [OH-] = x
So, Kw = \(x^2\) = (5.5 x \(10^-14\))
Taking the square root of both sides gives:
x = sqrt(5.5 x \(10^-14\)) = 7.42 x \(10^-8\)
Therefore, the pH of pure water at 50°C can be calculated using the formula:
pH = -log[H+]
pH = -log(7.42 x \(10^-8\)) = 7.13
The closest answer choice is e) 7.00.
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Which best describes a semiconductor?
a.)Semiconductors are more conductive than a nonmetal and less conductive than a metal.
b.)Semiconductors are more conductive than a nonmetal and less conductive than a metalloid.
c.)Semiconductors have a high electrical conductivity.
d.)Semiconductors have a no electrical conductivity.
Answer:
a.)Semiconductors are more conductive than a nonmetal and less conductive than a metal.
Explanation:
Answer: A is your answer
Explanation: yor welcome =]=]=]=]
HELP PLEASEE
Name three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts
Answer:
Let's start with the fact that cereals , are made of grains and are mostly carbohydrates. therefore they contain carbon oxygen and hydrogen. They also contain proteins so have nitrogen. Plants have the minerals that are in the soil where they grow, so the list you have is correct. They also generally have added vitamins ad minerals. The vitamins contain C, H, O N, and a few others such as sulfur, The added minerals might contain:copper, iron, zinc, cobalt, selenium, silicon and molybdenum .
Mark me as brainliest if it was helpful
The three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts are Iron, Calcium, and Zinc
Cereals are monocotyledonous grass crops cultivated annually for the purpose of consumption. They are rich in fiber and energy. Examples of them include;
maize, barley, wheat, oat, rye, etc.Cereal drinks are processed drinks extracted from cereal crops through fermentation. They are rich in nutrients as they contain important sources of carbohydrates, dietary protein, and vitamins.
The ingredients present in a cereal drink are composed of essential elements such as:
copper, cobalt, iron, zinc, molybdenum, iodine, chromium, and selenium.Some of which are not listed in the nutrition facts are Iron, Calcium, and Zinc.
Therefore, we can conclude that the elements present in the ingredients of the cereal drink which are not listed in the nutrition facts can be Iron, Calcium, and Zinc.
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What is the amount of moles of NaOH, if the solution molarity is .33 M NaOH in 0.75 L solution
Answer:
The amount of moles of NaOH is 0.0495
Explanation:
Molarity is a measure of concentration that is defined as the number of moles of solute that are dissolved in a given volume.
In symbolic form molarity is presented as:
\(Molarity=\frac{number of moles of solute}{volume}\)
Molarity is expressed in units \(\frac{moles}{liter}\).
In this case:
Molarity= 0.33 MNumber of moles of solute= ?Volume= 0.75 LReplacing in the definition of molarity:
\(0.33 M=\frac{number of moles of solute}{0.75 L}\)
number of moles of solute= 0.33 M* 0.75 L
number of moles of solute= 0.0495 moles
The amount of moles of NaOH is 0.0495
Answer:
0.248 moles of NaOH
Explanation:
Concept of Molarity is mol/L
[x] = 1 M
1 mol of x contained in 1 L of solution. We write molar concentrations between []
M = mol/L then M . L = mol
Our solution is NaOH
0.33 M . 0.75L = mol
This solution contains 0.248 moles of NaOH
Given the following equation: 2C6H6 + 15O2 - 12CO2 + 6H2O
How many moles of O2 are needed to react with 4.0 moles of
C6H6?
A. 30 Moles
B. 12 moles
C. 4.0 moles
D. 24 moles
Answer: 30 moles
Explanation:
2C6H6 + 1502 -------> 12CO2 + 6H2O from reaction
2 mol 15 molgiven 4.0 mol
x molx = 4.0*15/2 = 30. mol
how many moles of neon occupy a volume of 14.3 l at stp?
Answer: 0.638 moles
Explanation: A total of 0.638 moles of neon are needed to occupy a volume of 14.3 L at standard temperature and pressure (STP).
> A Moving to another question will save this response. Question 1 What is the mass number of an atom of potassium that has 20 neutrons?
a. 35
b. 59
c. 39
d. 15
e. 19
The mass number of an atom of potassium that has 20 neutrons is option C. 39
Mass number-
Mass number is the total number of protons and neutrons in the nucleus of an atom is called the mass number. It is represented by the symbol A. In other words, mass number refers to the sum of the number of protons and neutrons in the nucleus of an atom.
Atom-
Atoms are tiny particles that make up everything in the world. Everything in the world is made up of tiny particles known as atoms. An atom is the basic unit of matter. The term "atom" comes from the Greek word atomos, which means indivisible.
The basic building blocks of all matter are atoms, which are made up of three types of particles: protons, neutrons, and electrons.
In a neutral atom, the number of electrons is equal to the number of protons, thus the overall charge on the atom is zero. However, the mass number of the atom is equal to the sum of the number of protons and neutrons.
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Aqueous sulfuric acid H2SO4 will react with solid sodium hydroxide NaOH to produce aqueous sodium sulfate Na2SO4 and liquid water H2O. Suppose 17. g of sulfuric acid is mixed with 7.07 g of sodium hydroxide. Calculate the maximum mass of sodium sulfate that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.
Answer:
ok let me study into this first
Explanation:
I'll answer this in a few
Answer:
Maas of sodium sulphate produced = moles×molar mass=0.06×142=8.52 gmoles\times molar\ mass=0.06\times 142=8.52\ gmoles×molar mass=0.06×142=8.52 g
Explanation:
Reaction between them is given by-
2NaOH +H2SO4 → Na2SO4 +2H2O2NaOH\ \ +H_2SO_4\ \to\ Na_2SO_4\ \ +2H_2O2NaOH +H2SO4 → Na2SO4 +2H2O
Molar mass of H2SO4=98 g mole−1H_2SO_4=98\ g\ mole^{-1}H2SO4=98 g mole−1
Moles of sulphuric acid taken = 5.8898=0.06 mole\frac{5.88}{98}=0.06\ mole985.88=0.06 mole
Moles of sodium hydroxide taken = 6.240=0.155 mole\frac{6.2}{40}=0.155\ mole406.2=0.155 mole
here sulphuric acid is limiting agent so
reaction will proceed according to sulphuric acid
0.06 mole HSO4 will produce same amount of Na2SO40.06\ mole\ H_SO_4\ will \ produce\ same\ amount\ of \ \ Na_2SO_4\\0.06 mole HSO4 will produce same amount of Na2SO4
A solution made by dissolving 25. 0 mg of insulin in 5. 00 mL of water has an osmotic pressure of 15. 5 mmHg at 25°C. Calculate the molar mass of insulin. (Assume that there is no change in volume when the insulin is added to the water and that insulin is a non-dissociating solute. )
The molar mass of insulin is approximately 0.798 g/mol, calculated using the equation for osmotic pressure and the given values of mass and volume.
To calculate the molar mass of insulin, we can use the equation for osmotic pressure:
π = (n/V)RT
where π is the osmotic pressure, n is the number of moles of solute, V is the volume of the solution in liters, R is the ideal gas constant, and T is the temperature in Kelvin.
First, convert the given values to appropriate units:
25.0 mg = 0.025 g
5.00 mL = 0.005 L
Next, rearrange the equation to solve for n (number of moles):
n = (πV) / (RT)
Substituting the given values:
n = (15.5 mmHg * 0.005 L) / ((0.0821 L·atm/(mol·K)) * 298 K)
Calculate n:
n ≈ 0.0313 mol
Finally, divide the mass of insulin (0.025 g) by the number of moles (0.0313 mol) to find the molar mass:
Molar mass = 0.025 g / 0.0313 mol
Molar mass ≈ 0.798 g/mol
So, the molar mass of insulin is approximately 0.798 g/mol.
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Will combining water and baking soda make a chemical reaction?
Answer:
The baking powder reacts with water to produce bubbles, while baking soda does not react with water.
Explanation:
Answer:
yes
Explanation:
no
what is the product of the combustion of hydrogen
Answer:
Hydrogen burns in oxygen to form water. The flame is almost colourless. Mixtures of hydrogen and oxygen (or hydrogen and air) can be explosive when the two gases are present in a particular ratio, so hydrogen must be handled very carefully.
half-reaction for the oxidation of solid iodine dioxide IO2 to iodate ion IO−3 in basic aqueous solution.
The half reaction will be IO² (j) 6 OH⁻ (aq) → IO³⁻ (aq) 3H₂O (I) 6e⁻.
In this reaction, IO₂ is oxidized to IO³ losing 6 electrons. Hydroxide ions (OH⁻) are added to balance the charge on both sides of the equation, and water molecules are formed as products.
The oxidation of solid iodine dioxide (IO²) to iodine ion (IO³⁻) can be described by the following half-reaction in an alkaline aqueous solution:
IO² (j) 6 OH⁻ (aq) → IO³⁻ (aq) 3H₂O (I) 6e⁻
Note that this is a half-reaction of the oxidation process. To obtain a complete balanced equation for a redox reaction involving IO₂ and some other species, you must also write the half-reaction for the reduction process and balance the number of electrons transferred.
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The question is incomplete, the complete question is:
What is half-reaction for the oxidation of solid iodine dioxide IO2 to iodate ion IO−3 in basic aqueous solution?
which shows how much electron is in the outer layer
Answer:
is there a picture or is it multiple choice?
Which statement is true with respect to the investigation? The student investigated only the physical properties of lead. The student investigated only the chemical properties of lead. The student investigated more physical properties than chemical properties of lead. The student investigated more chemical properties than physical properties of lead.
The question is incomplete, the complete question is;
A student investigated some properties of lead and recorded the findings in the table below. Property Observation Color Dull gray Density 11.3 g/cm3 Volume of sample 3 cm3 Melting point 327°C Reaction with air Lead oxide forms on the surface Electrical conductivity Conducts some electricity Which statement is true with respect to the investigation?
A. The student investigated only the physical properties of lead.
B. The student investigated only the chemical properties of lead.
C. The student investigated more physical properties than chemical properties of lead.
D. The student investigated more chemical properties than physical properties of lead.
Answer:
The student investigated more physical properties than chemical properties of lead.
Explanation:
If we look at the things mentioned in the question as regards the approach of the student towards the study of lead, we will discover that he/studied;
Colour, density, volume, melting point and electrical conductivity which are all physical properties. Physical properties of a substance does not involve chemical reactions of the substance under study.
The only chemical property studied by the student is its formation of an oxide- lead oxide with air as follows;
2Pb(s) + O₂(g) → 2PbO(s)
Thus we can safely conclude that; the student investigated more physical properties than chemical properties of lead.
Answer:
c
Explanation:
edge 2021 :)
What happens during high tide?
a.The tidal range is at its minimum in a location.
b.The tidal range is at its maximum in a location.
c.The water level in the ocean rises to above average water level.
D.The water level in the ocean drops to below average water level.
Answer: c
Explanation:
HELP MEEEEEEEEEEEE
Winds and ocean breezes occur due to _____________.
A. None of these
B. Conduction currents
C. Boiling
D. Convection currents
Answer:
B
Explanation:
it flows by the conduction currents
A sample of hydrogen changes its pressure from 756 torr to 499 torr while the temperature remains constant. After the pressure is reduced, the volume of the gas is 789 mL. What was the original volume?
P1 = 756 torr
P2 = 499 torr
V2 = 789 mL
V1 = ?
applying Boyle's Law
P1 * V1 = P2 * V2
756 torr * V1 = 499 torr * 789 mL
V1 = 499 torr * 789 mL / 756 torr
V1 = 520.78 mL
(5.93 x 103) (2.3 x10-2)
Answer:
when you multpily or divide powers of 10 you just add or subratact respectivley
Explanation:
(5.93 x 10 ^ 3) (2.3 x 10^ -2) = (5.93 * 2.3 ) x 10 ^ 3 +(-2)
= 13.639 x 10 ^ 3-2
= 13 . 639 x 10
1.3639 x 10^2
dimethylhydrazine, (ch3)2nnh2, was used as a fuel for the apollo lunar descent module, with n2o4 being used as the oxidant. the products of the reaction are h2o, n2, and co2.
Dimethylhydrazine (CH₃)₂NNH₂ is a fuel used for the Apollo Lunar Descent Module, and N₂O₄ is the oxidant. During the reaction, H₂O, N₂, and CO₂ are produced.
The fuel and oxidizer were stored separately to prevent any accidental reaction before use. Once the engines were ignited, the dimethylhydrazine and N₂O₄ mixed and reacted, producing energy and the products mentioned above.
The fuel used in Apollo Lunar Descent Module was dimethylhydrazine (CH₃)₂NNH₂, whereas the oxidant was N₂O₄. The two substances were stored separately, and the reaction was initiated only when they were mixed. The reaction between the fuel and oxidant produced H₂O, N₂, and CO₂.
The reaction between dimethylhydrazine and nitrogen tetroxide was exothermic and highly energetic.The reason why dimethylhydrazine was chosen as the fuel is that it is highly flammable and can quickly produce large amounts of heat and energy when mixed with an oxidant.
This makes it an ideal fuel for rocket engines, especially those used in space exploration, where high-performance and efficiency are critical.
The reaction between dimethylhydrazine and nitrogen tetroxide is also highly stable and controllable, making it suitable for use in the Apollo Lunar Descent Module.
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The science department keeps two acid solutions on hand. One is 14% acid and the
other is 46% acid. How much 14% acid solution and how much 46% acid solution need to be mixed to
make 100 gallons of 35.8% acid solution?
34.3gallon of 14% acid solution and 65.7gallon of 46% acid solution need to be mixed to make 100 gallons of 35.8% acid solution.
What is gallon?A gallon is the standard unit of volume indicated by the letter "gal," and it is primarily used to measure liquid quantity inside the customary systems of the United States as well as the Imperial System of measuring of the United Kingdom.
Following the 11th Conference on Measures and Weights in 1960, some countries approved an International System of Units (SI). As a result, this volume measurement unit is replaced by "litre."
0.14×x + 0.46×(100-x)= 0.35×100
0.14x + 46-0.46x=35
-0.32x=35 -46
-0.32x =-11
x=11/ 0.32=34.3gallon
100-34.3=65.7gallon
Therefore, 34.3gallon of 14% acid solution and 65.7gallon of 46% acid solution need to be mixed to make 100 gallons of 35.8% acid solution.
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A substance conducts electricity because of free moving, charged particles.
what are the free moving charged particles in a :
carbon electrode(made of graphite)
molten mixture of aluminum oxide and cryolite
metal wire?
Answer:
carbon electrode: delocalised electrons
molten mixture....: aluminium oxide ions
metal wire: Metal atoms
The free moving charged particles in the following substances are as follows;
carbon electrode(made of graphite); Delocalized electrons.molten mixture of aluminum oxide and cryolite;. Aluminium ions in Aluminium oxide.Metal wire; Metal ionsGraphite, an allotrope of carbon has Delocalized (free-moving) electrons and these electrons serve to enable conductivity.
Although, cryolite is a bad conductor of electricity, when Molten Aluminium oxide and cryolite is used, the free moving Aluminium ions enable conductivity.
In metal wires, conductivity is solely the responsibility of metal ions.
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What is 1 mole of CO2?
1 mole of CO2 is 6.022 x 10^23 molecules of CO2. It is also 44.01 g of CO2. Here 44.01 g comes as the sum of individual atoms of CO2 i.e. 12.01 + 16 + 16 i.e. 44.01 g
CO2 is composed of one carbon atom and two oxygen atoms, which have the atomic masses of 12.01 g/mol and 16.00 g/mol respectively. So, the molar mass of CO2 is the sum of the atomic masses of the atoms that make up CO2, which is 12.01 + 16.00 + 16.00 = 44.01 g/mol. Carbon dioxide (CO2) is a naturally occurring compound made up of one carbon atom and two oxygen atoms. It is a colorless, odorless gas and is a byproduct of many biological and industrial processes. CO2 is a greenhouse gas, which means it helps trap heat in the Earth's atmosphere and contributes to global warming.
Therefore, one mole of CO2 weighs 44.01 grams.
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How do carbon atoms form many organic compounds
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.
a wrong
b wrong
c right
d wrong
Convert the following from moles to number of particless
32.45 mol Cr3(PO4)2 = ____ formula units Cr3(PO4)2
1.958 x 10²⁵ formula units of Cr₃ (PO₄) ² are present in 32.45 mol of Cr₃(PO₄) ².
What is mole?A mole is a unit used to quantify a substance's quantity. One mole of a substance is the volume of that substance that contains exactly 12 grams of carbon-12's weight in atoms (or other elementary particles like ions, molecules, or atoms).
How do you determine it?We need to use Avogadro's number, which is roughly 6.02 x 10²³ particles per mole, to convert from moles to formula units.
We must first figure out how many units of the formula there are in a mole of Cr₃ (PO₄) ². One Cr³⁺ ion and two PO₄³⁻ ions make up the formula unit for Cr₃ (PO₄) ². As a result, we can get the total number of ions in one unit of the formula as:
1 Cr³+ ion + 2 PO₄⁻³ ions = 3 ions.
Consequently, make up one mole of Cr₃ (PO₄) ²: 6.02 x 10²³ particles /mole = 3 ions / formula unit= 1.806 x 10²⁴ ions/mole.
Using the conversion factor below, we can determine how many formula units are contained in 32.45 moles of Cr₃ (PO₄) ²:
5.875 × 10²⁵ ions = 32.45 moles x 1.806 x 10²⁴ ions/mole.
Because Cr₃ (PO₄) ² has a formula unit of 3 ions, we can calculate the number of formula units by dividing the total number of ions by 3.
5.875 x 10²⁵ ions/3 ions/formula unit = 1.958 x 10²⁵ formula units.
Consequently, 1.958 x 10²⁵ formula units of Cr₃ (PO₄) ² are present in 32.45 mol of Cr₃(PO₄) ².
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A solution of NaCl was prepared in the following manner: 0.0842 g of NaCl is massed out on an analytical balance. The solid is transferred to a 25.00 mL volumetric flask. Deionized water is added to the flask such that the bottom of the meniscus is at the line. A 1.00 mL aliquot of the stock solution is transferred to a 50.00 mL volumetric flask using a volumetric pipet and diluted to volume. 6. Calculate the concentration of NaCl in the resulting solution in mg/L NaCl. (answer = 67.4 mg/L) 7. Calculate the concentration of NaCl in the resulting solution using propagation of error through the calculation. Use the manufacturer's tolerance values as the absolute error. The tolerances can be found in Chapter 2 of the Harris text. Assume a Class 1 balance and Class A glassware. Treat the tolerances as random error. (answer = 67.4+0.4 mg/L) 8. Identify 2 possible sources of random (indeterminate) error. Identify 2 possible sourses of systematic (determinate) error.
Two possible sources of systematic (determinate) error in the experiment are; Incorrect calibration of volumetric glasswareIncorrect mass of NaCl
To calculate the concentration of NaCl in the resulting solution in mg/L NaCl, we can use the formula; Concentration (mg/L) = (Mass of solute ÷ Volume of solution in L) × 1000 g / 1 mg NaCl is present in the stock solution of 25 mL. So, the mass of NaCl in the solution would be;0.0842 g ÷ 25 mL = 0.00337 g/mL. Now, in the resulting solution, a 1.00 mL aliquot of the stock solution is transferred to a 50.00 mL volumetric flask and diluted to volume. Therefore, the volume of the resulting solution is 50.00 mL. We will substitute these values in the formula, Concentration (mg/L) = (0.00337 g/mL ÷ 50 mL) × 1000 g / 1 mg concentration (mg/L) = 67.4 mg/L. Therefore, the concentration of NaCl in the resulting solution in mg/L NaCl is 67.4 mg/L.7. Concentration = 67.4 mg/LTolerance = 4.28 mg/LTotal concentration = 67.4 + 4.28 mg/L = 71.68 mg/LWe round off this value to one decimal place; Total concentration = 71.7 mg/LTherefore, the concentration of NaCl in the resulting solution using propagation of error through the calculation is 67.4+0.4 mg/L.8. Two possible sources of random (indeterminate) error in the experiment are; Errors in temperature measurement. Errors in measurement of water volume. Two possible sources of systematic (determinate) error in the experiment are; Incorrect calibration of volumetric glasswareIncorrect mass of NaCl.
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Which of these is an example of a reaction that absorbs energy?
A. a cake baking
B. a candle burning
C. a firework exploding
D. a piece of wood smoldering
Answer:
I think its B
Explanation:
because a energy that occurs is thermal energy
An aluminum bar was found to have a mass of 27g. Using water displacement, the volume was measured to be 10 ml. What is the density of the aluminum? Group of answer choices (27 g)/(10 ml) (10 ml )/(2.70 g) (270 g)/(10 ml) (10 ml )/(27 g)
Answer:
2.7 g/mL:)
An aluminum bar was found to have a mass of 27g. Using water displacement, the volume was measured to be 10 ml. What is the density of the aluminum? Group of answer choices (27 g)/(10 ml) (10 ml )/(2.70 g) (270 g)/(10 ml) (10 ml )/(27 g)
Density is an intensive property as it does not depend on the quantity of the substances Whereas mass and volume are extensive property. Therefore, the density of the aluminum bar is 2,700 g/L or 2.7 g/mL.
What is density?Density tells about the compactness of the substances, how much dense is the substances in other words. Object that is more denser than water they just sink in the water.
Mathematically,
Density of aluminum bar = Mass of aluminum bar ÷volume marked on the graduated cylinder
Mass of aluminum bar= 27g
volume of aluminum bar= 10 ml=0.01L
substituting all the given values in the above equation, we get
density= 27g /0.01L
On calculations, we get
density= 2,700 g/L or 2.7 g/mL
Therefore, the density of the aluminum bar is 2,700 g/L or 2.7 g/mL.
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A gas has a volume of 350 ml at 45oC. If the volume changes to 400. ml, what is the new temperature in oC
Answer:
It should be 28 degrees C
Explanation:
Answer:
28°C
Explanation:
3. When a new substance is formed with different properties than the original substance it
is called a
A. Chemical change
B. Physical change
C. Freezing
D. Boiling
Answer:
A) Chemical Change
Explanation:
Chemical changes occur when bonds are broken and formed between molecules or atoms. This means that one substance with a particular set of properties (such as melting point, color, taste, etc.) is turned into a different substance with different properties.
In your own words, describe the process of convection.
Answer:
the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat
Explanation:
<3
Answer:
Convection when heat travels through metal or appliances.
Explanation:
_________ are elements of the same element that have a different _______________ due to a different number of _____________.
Answer: Isotopes
Explanation:
The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses.
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