Question

1. At STP, you have 0.101 g of carbon dioxide gas. What is the volume of this gas?

Answer 1

Answer:

1) A. 0.0515 L

2) B. 35.504 L

3) B. 422.446 g

Explanation:

At STP, you have 0.101 g of carbon dioxide gas. What is the volume of this gas?

Step 1: Data given

Mass of   CO2 gas = 0.101 grams

Molar mass of CO2 = 44.01 g/mol

STP = 1 atm and 273K

Step 2: Calculate moles CO2

Moles CO2 = mass CO2 / molar mass CO2

Moles CO2 = 0.101 grams / 44.01 g/mol

Moles CO2 = 0.0023 moles

Step 3: Calculate the volume

For 1 mol at STP we have 22.4L

0.0023 moles we have 22.4L * 0.0023 = 0.0515 L

Option A is correct

You have 27g of ammonia (nitrogen trihydride) at STP. What is the volume? Hint...you will first need to convert mass of ammonia to moles!

Step 1: Data given

Molar mass of NH3 = 17.03 g/mol

Mass of NH3 = 27.00 grams

STP = 1 atm and 273K

Step 2: Calculate moles NH3

Moles NH3 = 27.00 grams / 17.02 g/mol

Moles NH3 = 1.585 moles

Step 3: Calculate volume

For 1 mol at STP we have 22.4 L

For 1.585 moles we have 22.4 * 1.585 = 35.504 L

Option B is correct

Which of the following represents the MASS of 215 L of dinitrogen monoxide at STP? Hint...find the # of moles of this gas and then use the molar mass to go from moles to mass!

Step 1: Data given

Volume = 215 L

STP = 1 atm and 273 K

Molar mass of N2O = 44.01 g/mol

Step 2: Calulate moles N2O

22.4L = 1 mol at STP

215 L = 215 / 22.4 = 9.60 moles

Step 3: Calculate mass N2O

Mass N2O = moles N2O * molar mass N2O

Mass N2O = 9.60 moles* 44.01 g/mol

Mass N2O = 422.446 g

Option B is correct