# Question #47cfa

##### 2 Answers

The mass of

**Start with a balanced equation, which you have.**

**Determine the mole:mole ratio for #"CaCO"_3# and #"CO"_2#.**

**Determine the molar mass of #"CaCO"_3# and #"CO"_2#.**

Molar mass of

Molar mass of

**Determine the number of moles of #"CaCO"_3# in #1.25 "g CO"_2"#.**

**Determine the number of moles of #"CO"_2#.**

**Determine the mass of #"CO"_2#by multiplying moles times molar mass.**

**Determine the volume of #"CO"_2# at STP.**

Use the ideal gas law equation

STP for gases is

**Given/Known:**

**Unknown:**

**Now rearrange the ideal gas equation in order to isolate and solve for #V#.**

CaCO3(s) --> CaO(s) + CO2(g)

The first step to this problem is to find the number of moles that can be obtain from 1.25g.

Formula: **(mass/relative molecular mass)**

You will obtain an amount of 0.0125 moles. **Your equation should be (1.25g/100)**

STP (Standard Temperature Pressure) states the volume of a gas when it's at a standard temperature of 273K and 1atm. At STP, one mole of gas occupies 22.4 L of molar volume.

Therefore, multiply 0.0125 moles of CaCO3 with 22.4 L of molar volume at STP. Your final answer should then be **0.2800L of CO2.**