4.) The temperature of solid silver increases from 30C to 40C by the addition of 117.5 joules of heat. What is the mass of the silver?

The mass of silver is 49 g (0.049 kg).

Explanation:

Initial temperature = C

Final temperature = C

Quantity of heat required = 117.5 J

Specific heat capacity of silver = 0.240 J/g

mass of the silver can be determined by;

Q = mcΔθ

Where: Q is the quantity of heat required, m is the mass of substance, c is the specific heat capacity of the substance and Δθ is the change in temperature.

So that,

117.5 = m x 0.240 x (40 - 30)

117.5  = m x 0.24 x 10

        = 2.4m

m =

   = 48.9583

m ≅

m = 49 g

The mass of silver is 49 g (0.049 kg).

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

a