Homework Sourse25 The formula for phosphorus pentachloride is PCL5 How man
25. The formula for phosphorus pentachloride is . PCL5
How many molecules are in 1.75 grams of phosphorus pentachloride?
molecules
What is the mass in grams of 6.66x10^22 molecules of phosphorus pentachloride?
grams
The formula for lead(II) nitrate is . Pb(NO3)2
How many grams of lead(II) nitrate are present in 4.48x10^22 formula units of this compound?
grams
How many formula units of lead(II) nitrate are present in 4.15 grams of this compound?
formula units
30. The compound NH4NO3 can be decomposed to form N2O and H2O. This can be represented at the atomic level by a chemical equation:
According to the law of conservation of mass, if 29.7 grams of NH4NO3 decomposes and 16.3 grams of N2O is formed, how many grams of H2O must simultaneously be formed?
grams H2O
The compound NO can be formed by combining N2 and O2. This can be represented at the atomic level by a chemical equation:
According to the law of conservation of mass, if 21.9 grams of N2 and 25.0 grams of O2 combine to form NO, how many grams of NO must form? grams NO
33.
We can interpret this to mean:
React to produce
Interpret the following equation for a chemical reaction using the coefficients given:
On the molecular level:
_________one moleculetwo moleculesone moletwo moles of H2(g) reacts with _________one moleculetwo moleculesone moletwo moles of F2(g) to form _________one moleculetwo moleculesone moletwo moles of HF(g).
On the macroscopic level:
One mole of H2(g) reacts with _________one moleculetwo moleculesone moletwo moles of F2(g) to form _________one moleculetwo moleculesone moletwo moles of HF(g).
| We can interpret this to mean: | ||||||
| ... | 1 | mole of | water | and | moles of | carbon monoxide |
|
| ||||||
| ... | moles of | carbon dioxide | and | moles of | hydrogen |
Solution
I am solving the first 2-problems containing 4-subparts as per Chegg guidelines, post multiple question to get the remaining answers
Q25)
Molar mass of PCl5 = 31 + 35.45 * 5 = 208.25 gm/mol
Number of moles of PCl5 = Mass/molar mass = 1.75/208.25 = 0.008403 moles
Number of molecules = 0.008403 * 6.023 * 10^(23) = 5.061 * 10^(21) molecules
Mass in grams of 6.66 * 10^(22) molecules = 6.66 * 10^(22)/6.023 * 10^(23) = 0.11057 moles
Mass = 0.11057 mol * 208.25 gm/mol = 23.026 grams
Q)
Molar mass of Pb(NO3)2 = 331.2 gm/mol
Mass in grams of 4.48 * 10^(22) molecules = 4.48 * 10^(22)/6.023 * 10^(23) = 0.07438 moles
Mass = 0.07438 mol * 331.2 gm/mol = 24.635 grams
Number of moles of PCl5 = Mass/molar mass = 4.15/331.2 = 0.01253 moles
Number of molecules = 0.01253 * 6.023 * 10^(23) = 7.546 * 10^(21) molecules
