<h3>
Answer:</h3>
250.756 moles He
<h3>
Explanation:</h3>
From the question we are given;
Volume, L = 685 L
Temperature, T = 621 K
Pressure, P = 189 × 10 kPa
We are required to calculate the number of moles of the gas,
Using the Ideal gas equation,
PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.
We can replace the known variables and constant in the equation to get the unknown variable, n.
Using ideal gas constant as 8.3145 L.kPa/K/mol
n = 250.756 moles
The moles of helium contained in the sphere is 250.756 moles
In order to find out the %mass dolomite in the soil,
calculate for the mass of dolomite using the information given from the
titration procedure. You would need to multiply 57.85 ml with 0.3315 M HCl and
you would get the amount of HCl in millimoles. Then multiply the amount of HCl
with 1/2 (given that for every 1 mol of dolomite, 2 mol of HCl would be
needed). Convert the amount of dolomite to mass by multiplying the millimoles
with the molecular weight which is 184.399. Then convert the mass to grams
which is 1.768 grams. Divide the mass of dolomite (1.768 grams) with the weight
of soil sample. The % mass is 7.17.
Answer:
Ke = 34570.707
Explanation:
- H2(g) + Br2(g) → 2 HBr(g)
equilibrium constant (Ke):
⇒ Ke = [HBr]² / [Br2] [H2]
∴ [HBr] = (37.0 mol) / (2 L) = 18.5 mol/L
∴ [Br2] = (0.110 mol) / (2 L) = 0.055 mol/L
∴ [H2] = (0.360 mol) / (2 L) = 0.18 mol/L
⇒ Ke = (18.5 mol/L)² / (0.055 mol/L)(0.18 mol/L)
⇒ Ke = 34570.707
