Answer:
pH = 2.88
Explanation:
For a weak acid solution, the pH can be calculated using the following formulas:
[H⁺] = [tex]\sqrt{Ka*C}[/tex]pH = -log[H⁺]Where Ka = [tex]10^{-pKa}[/tex] and C is the molar concentration.
We are given Ka and C by the problem, meaning we can now proceed to calculate [H⁺]:
[H⁺] = [tex]\sqrt{1.7*10^{-4}*0.01}[/tex] [H⁺] = 0.0013 MFinally we calculate the pH:
pH = - log (0.0013) = 2.88Calculate the number of nickel atoms in a 5-cent coin of mass 0.942g if it was made of an alloy consisting of 75% copper and 25% nickel.
Answer:
2.41x10²¹ atoms
Explanation:
First we calculate the mass of nickel in the coin, using the given mass and percent composition:
0.942 g * 25/100 = 0.2355 g NiThen we convert 0.2355 grams of nickel to moles, using its molar mass:
0.2355 g Ni ÷ 58.69 g/mol = 0.004 molFinally we convert moles into number of atoms, using Avogadro's number:
0.004 mol * 6.023x10²³ atoms/mol = 2.41x10²¹ atoms1. During an endothermic chemical reaction, a gas is consumed and a liquid produced.
a. Yes.
b. No.
c. Can't decide with information given.
2. A gas condenses to a liquid, neither absorbing nor releasing heat.
a. Yes.
b. No.
c. Can't decide with information given.
Anyone know the answer
Answer:
b
Explanation:
i know
Explain why a city that receives 10 hours more light each day has colder average temperatures. Explain
Explanation:
This would be similar to how the poles work in the North and South. Due to their placement, they recieve much more sun light than the rest of the Earth since we rotate horizontally. However, their placement also makes them farther from the sun than the rest of Earth, therefore not receiving as much heat.
What volume (in mL) of concentrated HCl (12 M) is needed to make 1500 mL of a 3.5 M solution?
Answer:
437.5 mL
Explanation:
Concentration (c) = Moles (n) / Volume of solution (liters)
C = n / V
rearrange the formula to find out how many moles you need in the final solution.
n (moles) = concentration (c) x Volume (V) ( in liters)
Convert your mL into L. 1500mL is 1.5L
n = 3.5 moles/liter x 1.5 liters (the liters cancel each other out)
n = 5.25 moles
Now use the same formula to calculate the volume you need to make the final solution based on the concentration of the original.
c = n/V or V = n / c
V = 5.25 moles / 12 moles/liter here the moles cancel out
V = 0.4375 L
convert back to mL
V = 437.5 mL
USA test prep wave 1 performance task
Answer:
Performance Tasks 188; Instructional Videos 75
Explanation:
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
what is the most important part of solution preparation
Answer:
id k exactly what your asking
Explanation:
PLEASE HELP!!! I will mark brainliest I am really struggling with these problems
Answer:
21883.75 Joules are required to melt the ice!
cosity a letter to our mother
who is in lagos Nigeria telling
her about the
the problem you are
facing
in the school and at
home and suggest solution to
you pproblem
N 2H 4 + H202 N2 + H 20
Answer:
N2 + H20
Explanation:
chemical equation balancer
7th grade science lol help
Answer:
C) Organic Weathering
Explanation:
Heat and Cold
And if some people start reporting and making fun of me in this answer don't listen to them.
They are hunting me down.
2. A chemical's flash point is the
How many moles would be present in a gas contained in a 100.0 mL vessel at 25.0oC at a pressure of 2.50 atm?
Answer:
n = 0.0102 mol.
Explanation:
Hello there!
In this case, according to the ideal gas law, which allows us to set up a relationship among volume, pressure, temperature and moles, we can define it as:
[tex]PV=nRT[/tex]
Thus, given the volume in liters (0.1000 L), temperature in kelvins (298.15 K) and pressure in atmospheres (2.50 atm), we can solve for moles as shown below:
[tex]n=\frac{PV}{RT}[/tex]
Thereafter, we plug in the aforementioned values to obtain:
[tex]n=\frac{2.50atm*0.1000L}{0.08206\frac{atm*L}{mol*K}*298.15K}\\\\n=0.0102mol[/tex]
Best regards!
Which of the following is the best explanation of why an ionic compound formula is a ratio of atoms
ООО
The sharing of electrons is always in a simple ratio
The number of atoms in an ionic compound change... there can be several possible combinations
When ions form they are attracted to each other and "cxmp" together to form a crystal
lonic compounds conduct electricity when dissolved in water.
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
Answer:
c. 10–14[H3O+]
Explanation:
On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34). Example: What is the pOH of a solution that has a hydroxide ion concentration of 4.82 x 10-5 M? The hydroxide ion concentration can be found from the pOH by the reverse mathematical operation employed to find the pOH.
Which letter indicates the most sudden change in temperature
Answer:
J 9. , indicates the most sudden change in temperature
A hydrogen fuel cell is an electrochemical reactor in which oxygen and hydrogen gas are reacted to produce energy. Rather than combusting hydrogen in the presence of oxygen, the overall reaction (1/2) O2 H2 → H2O is actually carried out as two `half-reactions’ occurring at separate electrodes. To complete the reaction, this forces electrons to pass through an external circuit from one electrode to the other, and this current can be used to do work; e.g., by driving a motor. Typical operating conditions for a solid-oxide fuel cell are 500-900 C and 5-15 bar. Consider a fuel cell in which a pure oxygen stream and a pure hydrogen stream enter at 11 bar and 700 C with stoichiometric flowrates. Assume that these reactants are consumed completely, and that the water generated by the reaction leaves in a third stream at the same T and P. Assume that the fuel cell operates at steady-state with a uniform temperature of 700 C. a) Write simplified first and
Answer:
(d) Why is the fuel cell in Question (c) described as an alkaline fuel cell? (e) Another type of fuel cell uses methanol instead of hydrogen.
Explanation:
How many moles of carbon dioxide are produced when 0.25 mole of butane is consumed?
Answer:
1
Explanation:
Let's write the equation first:
[tex]C_{4}H_{10} + \frac{13}{2} O_{2} -> 4 CO_2 +5 H_{2}O[/tex]
So 1 mole of butane reacts to give 4moles of Carbon diOxide.
thus , 0.25 mole of butane will react to give = 4 * 0.25= 1 mole Carbon diOxide
A] 1 N2 + 3 H2 → 2 NH3
1. How many moles and grams of ammonia can be made from 6.3 moles of H2 ?
2. How many moles and particles of ammonia can be made from 2.5 moles of N2 ?
3. How many moles is 425 g of ammonia? How many moles and grams of N2 are needed to make it?
4. How many moles and grams and liters of H2 are needed to make 10 moles of ammonia?
I haven't done these in some time, so I'm not sure if they are 100% right.
1) 6.3 moles of H2( 2 mol of NH3 / 3 mol of H2)= 4.2 mol of NH3
6.3 moles of H2( 2 mol of NH3/ 3 mol of H2)(17.04 g of NH3/1 mol NH3)= 71.57 g of NH3
2) 2.5 moles of N2(2 mol of NH3/1 mol of N2)= 5 moles of NH3
2.25 moles of N2(2 mol of NH3/ 1 mol of N2)(6.02x10^23 particles/ 1 mol of NH3)= 3.01x10^24 particles of NH3
3) 425 g of NH3(1 mol of NH3/17.04 g NH3)= 24.9 moles of NH3
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)(28.02 g of N2/1 mol N2)= 349 g of N2
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)= 12.5 mol of N2
4) 10 moles NH3(3 moles of H2/2 moles of NH3)= 15 moles H2
10 moles NH3(3 mol of H2/2 mol of NH3)(2.02 g of H2/1 mol of H2)= 30.3 g of H2
30.3 g = .0303 liters of H2
QUESTION TWO
2.1
Discuss the process of the scientific method and clarify what is meant
by the science process skills.
(5)
Answer: The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observation.
Explanation:
Hope this helps. :)
How are nuclear fission and nuclear fusion similar?
A. Both processes combine smaller nuclei into larger nuclei.
B. Both processes convert mass into energy.
C. Both processes are used to produce electrical power.
D. Both processes occur in stars.
Answer:
C. Both processes convert mass into energy.
A gas with a volume of 4.0 L at a pressure of 0.9 atm is allowed to expand until the pressure drops to 0.20 atm. What is the new volume?
Answer: 25
Explanation:
The new volume will be 18 L
What is volume?The volume of a dry gas of a given mass was inversely proportional to its pressure at constant temperature, according to Boyle's law. At moderate pressures and temperatures, most gases behave like ideal gases.
Calculation of new volume is shown as below:
The new volume of can be calculated by using Boyle's law.
[tex]P_{1} V_{1} = P_{2} V_{2}[/tex]
It is given that, [tex]P_{1}[/tex] = 0.9 atm. [tex]V_{1}[/tex] = 4 L, [tex]P_{2}[/tex] = 0.20 atm
Now, put the values of given data in above equation.
[tex]V_{2}[/tex] = [tex]P_{1}V_{1}[/tex] / [tex]P_{2}[/tex].
[tex]V_{2}[/tex] = (0.9) ×4 / 0.20
= 3.6 / 0.20
= 18 L
therefore, the new volume will be 18 L.
To know more about volume.
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HELP! 20 mL of hydrogen measured at 15°C is heated to 35°C.
What is the new volume at the same pressure?
Answer:either 20.38 or 21.38
Explanation:
i clicked on 10.38 and it was wrong, i also clicked on 22.38 and it was wrong lol
Answer: 21.38 mL
Explanation: i just answered it on ck-12
Was rays birthday lit
Answer:
Yes.
Explanation:
Yes.
Answer:10-1707
Explanation:
How many moles are in 15.2 grams of Calcium (Ca)?
Answer:
There are 0.379 moles of Ca in the given sample.
Explanation:
Hey there!
We're given that we have 15.2 grams of Ca (Calcium). We need to convert grams to moles.
There are many different conversion types for moles. A few examples are:
grams to molesmoles to gramsgrams to particlesmoles to litersThere are really endless possibilities for conversion factors. Since we want to find the number of moles in a certain sample, we first need to define what a mole is.
Mole - a unit of measurement in chemistryA mole is one unit of a certain item. For instance, one cup would be equivalent to one mole. Moles are simply a hypothetical unit in chemistry that act as a placeholder.
Now, how do we find the number of moles?
We know that a mole of something is one of that substance. In this case, we're referring to one atom of Calcium.
Therefore, we need to reference a periodic table to understand what the mass of one atom of calcium is equivalent to. I'll be using the official AP Chemistry periodic table as issued by the College Board.
When we reference the periodic table, we see the mass of one atom of calcium is equivalent to 40.08 amu (atomic mass units).
We learn in chemistry that we can use the terms amu and grams interchangeably, so we have learned that one mole of calcium is equivalent to 40.08 grams.
How do we work this out?
Now, we need to find out how many moles are in 15.2 grams of calcium. We can use dimensional analysis to work this out.
Our starting unit will be 15.2 grams of Ca.
[tex]\text{15.2 grams Ca}[/tex]We want to convert this into moles, so we need to cancel out our grams value. Additionally, since we know that we have 40.08 grams of Ca in one mole, we can set these up as two ratios:
[tex]\displaystyle \frac{\text{40.08 grams Ca}}{\text{1 mole Ca}}[/tex][tex]\displaystyle \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]These ratios can be used to express the relationship between the moles of calcium and the mass of one calcium atom. However, we need our value of grams to cancel out, so since we will be using cross multiplication in our dimensional analysis, we need to use the ratio with grams on the bottom.
Now that we have selected our ratio, we can set up a multiplication problem of our two ratios:
[tex]\displaystyle \text{15.2 grams Ca} \times \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We assume that we have a denominator of 1 below 15.2 grams Ca.
Now, we perform our multiplication.
[tex]\displaystyle \frac{\text{15.2 grams Ca} \ \times \ \text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We see that our remaining unit is going to be mole(s) Ca, so we can go ahead and drop our grams Ca unit.
[tex]\displaystyle \frac{\text{15.2} \ \times \ \text{1 mole Ca}}{\text{40.08}}[/tex]
Now, we need to simplify a little bit.
[tex]\displaystyle \frac{\text{15.2}}{\text{40.08}} = \text{? moles Ca}[/tex]
Finally, let's divide our fraction and evaluate our equation to find the value of moles Ca.
[tex]\displaystyle \frac{15.2}{40.08} = \text{0.379241517 moles Ca}[/tex]
Are we done yet?
Not just yet! To complete our work, we need to find the number of significant figures we can use. We are given two values in which we can use to judge how many significant figures we are limited to.
15.2 -- Three significant figures40.08 -- Four significant figuresIn chemistry, we always use the least number of significant figures for precision calculations, so we need to round our answer to three significant figures.
[tex]0.379241517 \approx 0.379[/tex]
Therefore, there are approximately 0.379 moles of Ca in the given sample.
When planning a simple experiment, what does it mean to “test one variable”?
a During the experiment, the scientist keeps the control the same but changes many other elements he or she is testing.
b During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis.
c The scientist can only use simple language and materials when planning the one variable to be tested.
d The scientist plans and performs just one science experiment a day to test one variable.
Answer:
I believe the answer is "b". "During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis."
Explanation:
I remember from last year but I'm not totally sure. Good luck!
The experimental setup has been the design that includes the experimental and the control group. during the experiment, only one variable is changed to test the hypothesis. Thus, option b is correct.
What is experimental design?The experiment design includes the testing of the hypothesis to solve the problem and reach the solution through the analysis of the observations. It has been the setup that includes the test and the control group that involves the dependent, independent, and controlled variables.
Testing one variable in the experimental designs means changing one of the elements of the experience to prove the reliability of the hypothesis. This variable is the factor that alters and affects the other factors of the experiment and leads to a cause and effect.
The result of the effect of the hypothesis proves the testability of the experiment and provides solutions to the research question. This further leads to the formulation of the law and theory.
Therefore, option A. testing one variable involves proving the hypothesis.
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When copper is heated with an excess of sulfur, copper(l) sulfide is
formed. In a given experiment, 0.0970 moles of copper was heated
with excess sulfur to yield 5.59 g copper(1) sulfide. What is the
percent yield?
Answer:
72.4%
Explanation:
Step 1: Write the balanced equation
2 Cu + S ⇒ Cu₂S
Step 2: Calculate the theoretical yield, in moles, from 0.0970 moles of Cu
The molar ratio of Cu to Cu₂S is 2:1.
0.0970 mol Cu × 1 mol Cu₂S/2 mol Cu = 0.0485 mol Cu₂S
Step 3, Convert the theoretical yield to mass
The molar mass of Cu₂S is 159.16 g/mol.
0.0485 mol × 159.16 g/mol = 7.72 g
Step 4: Calculate the percent yield
We will use the following expression.
%yield = experimental yield/theoretical yield × 100%
%yield = 5.59 g/7.72 g × 100% = 72.4%
Can someone help me I am stuck on this question it would mean the world if u helped me =) have a nice day!
Name the following alkene:
CH3C = CH2
1
CH3
A. 2-methyl-1-propene
B. 2-methyl-2-propene
C. 1-propyl-2-methene
D. 2-methyl-1-propane
Pls help
The name of the given alkene is 2-methyl-1-propene. The correct option is A.
What are alkenes?
Alkenes are inorganic compounds. They are the series of hydrocarbons, that are formed by carbon-carbon double bonds. To find out alkenes, you have to see that the number of hydrogen atoms is always double the number of carbons.
Propene is an unsaturated compound, which is the second-simplest compound, and it contains a single double bond, and it is a colorless gas and has a texture of petroleum jelly.
CH₃C = CH₂
I
CH₃
Here, the three CH₃ are shown in the diagram, so it will be the methyl because it contains 3 CH₂, and now see the propene means one double bond and four carbon atoms. So it will be the 2-methyl-1-propene.
Thus, the correct option is A. 2-methyl-1-propene.
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