# Homework 59

- Page ID
- 28973

**10.44:**

__Question:__

The initial temperature for each substance, with an unknown mass, is and absorbs 2450 J of heat. Below, each final temperature is recorded with each substance. With what is given, what is the mass of each substance?

A. Silver ()

B. Water ()

C. Granite ()

__What we know: __

- Initial Temperature()
- Heat absorbed (2450 J)
- Final Temperatures (Silver:, Water:, Granite:)
- Specific Heats() (Silver: , Water:, Granite:).

__What it is asking for:__ The mass of each substance

__Strategy:__

- Find an equation suitable with the information given
- Plug in all the information given in the appropriate places in the equation
- Solve and get the mass for each substance

__Solution:__

Heat= m

m=mass = specific heat =()

__A. Silver__

**B. Water**

**C. Granite**

## 11.40:

__Question:__

We have a 20.0 L cylinder that is filled with 28.6 g of oxygen gas at the temperature of 401 K. What is the pressure that the oxygen gas is putting on the cylinder?

__What we know:__

- Molar mass of O
_{2}= 32 g/mol - Temperature is 401 K
- There is 28.6 g of Oxygen
- The volume is 20.0 L

__What its asking for: __The pressure of the gas

__Strategy:__

- Find an equation that goes with what information you are given
- plug in the information into the formula and get your answer

__Solution:__

Molar mass of O_{2}= 32 g/mol

Moles of O_{2} in 28.6 g= = 0.894 mol O_{2}

PV=nRT