Answer:
b) 0.47
Explanation:
MwC5H12 = 72.15g/mol
⇒mol C5H12 = (10.0)*(mol/72.15)=0.1386molC5H12
MwC6H14=86.18g/mol
⇒molC6H14=(20.0)*(mol/86.18)=0,232
MwC6H6=78.11g/mol
⇒molC6H6=(10.0)*(mol/78.11)=0.128molC6H6
<h3>XC6H14=(0.232)/(0.1386+0.232+0,128)=0.465≅0.47</h3>
You did not include the questions.
I did some research and found the questions:
<span>
What is the mass of 1 mole of pennies?
How many moles of pennies have a mass equal to the mass of the moon?
Solutions:
1) mass of 1 mole of pennies
Data: mass of 1 penny = 2.50 g
1 mole = 6.022 * 10^ 23 units
Proportion:
1 penny 6.022 * 10^23 penny
-------------- = ----------------------------
2.50 g x
Solve: x = 6.022 * 10^23 penny * 2.50g / 1 penny = 15.055* 10^23
Since 2.50 has 3 significant figures, the answer must use 3 significant figures => x = 15.1 * 10^ 23 g = 1.51 * 10^24 g
Answer: 1 mol of pennies have a mass of 1.51 * 10^24 g
2) How many moles of pennies have a mass equal to the same mass of the Moon
Convert the mass of the Moon grams: 7.35 * 10^22 kg = 7.35 * 10^ 25 g
1 mol x
---------------------- = ----------------------
1.51 * 10^ 24g 7.35 * 10^ 25 g
=> x = 7.35 * 10^ 25 g * 1 mol / (1.51 * 10^24 g)= 48.7 mol
Answer: 48.7 mol
</span>
Basis: 100 mL solution
From the given density, we calculate for the mass of the solution.
density = mass / volume
mass = density x volume
mass = (1.83 g/mL) x (100 mL) = 183 grams
Then, we calculate for the mass H2SO4 given the percentage.
mass of H2SO4 = (183 grams) x (0.981) = 179.523 grams
Calculate for the number of moles of H2SO4,
moles H2SO4 = (179.523 grams) / (98.079 g/mol)
moles H2SO4 = 1.83 moles
Molarity:
M = moles H2SO4 / volume solution (in L)
= 1.83 moles / (0.1L ) = 18.3 M
Molality:
m = moles of H2SO4 / kg of solvent
= 1.83 moles / (183 g)(1-0.983)(1 kg/ 1000 g) = 588.24 m
Answer:
2.12×10²³ atoms.
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This simply means that 1 mole of zirconium also 6.02×10²³ atoms.
Thus, we can obtain the number of atoms present in 0.3521 mole of zirconium as follow:
1 mole of zirconium also 6.02×10²³ atoms.
Therefore, 0.3521 mole of zirconium will contain = 0.3521 × 6.02×10²³ = 2.12×10²³ atoms.
Therefore, 0.3521 mole of zirconium contains 2.12×10²³ atoms.
Answer:
Chemicals A and B form an endothermic reaction, and chemicals C and D form an exothermic reaction.
Explanation:
The reaction that produced chemical C is an endothermic reaction whereas, the reaction between C and D is an exothermic one.
An exothermic change is one in which heat is liberated to the surroundings. So the surrounding becomes hotter at the end of the reaction.
An endothermic reaction is a change in which heat is absorbed from the surrounding and hence the surrounding colder at the end of the change.
- We can see that the first reaction is endothermic.
- The second reaction is exothermic.
