A syringe containing 1.63 mL of oxygen gas is cooled from 91.0 ∘C to 0.9 ∘C. What is the final volume Vf of oxygen gas? (Assume that the pressure is constant.) Vf = nothing mL Request Answer Provide Feedback

Vf = 1.22 mL

Explanation:

If we assume that the pressure is constant and the number of moles does not change, we can say that the volume of the gas is modified in a directly ratio, to the Absolute Temperature.

Let's convert the values:

91°C + 273 = 364K

0.9°C + 273 = 273.9K

Volume decreases if the temperature is decreases

Volume increases if the T° increases

V₁ / T₁  = V₂ / T₂ → 1.63mL /364K = V₂ / 273.9K

V₂ = (1.63mL /364K) . 273.9K → 1.22 mL

The final volume of the oxygen gas is 1.23 mL

Explanation:

Step 1: Data given

Volume of the syringe = 1.63 mL = 0.00163 L

Initial temperature = 91.0°C = 364.15 K

Final temperature = 0.9 °C = 274.05 K

Step 2: Calculate the final volume

V1/T1 = V2/T2

⇒with V1 = the initial volume = 0.00163 L

⇒with T1 = the initial temperature = 364.15 K

⇒with V2 = the final volume = TO BE DETERMINED

⇒with T2 = the final temperature = 274.05 K

0.00163/364.15 = V2 / 274.05

V2 = 0.00123 L = 1.23 mL

The final volume of the oxygen gas is 1.23 mL

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%