The mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the number of moles of a substance by its molar mass. That is;
Mass of Arsenic = no. of moles of As × molar mass of As.
According to this question, 6.12 moles of arsenic was given and its molar mass is 74.92g/mol.
Mass of As = 6.12 mol × 74.92g/mol
Mass of As = 459g
Therefore, the mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.
Learn more about mass calculations at: brainly.com/question/8101390
The answer is: 10
I could be wrong
The answer would have to be d because heat rises
1. 12 L = 12 dm³
2. 3.18 g
<h3>Further explanation</h3>
Given
1. Reaction
K₂CO₃+2HNO₃⇒ 2KNO₃+H₂O+CO₂
69 g K₂CO₃
2. 0.03 mol/L Na₂CO₃
Required
1. volume of CO₂
2. mass Na₂CO₃
Solution
1. mol K₂CO₃(MW=138 g/mol) :
= 69 : 138
= 0.5
mol ratio of K₂CO₃ : CO₂ = 1 : 1, so mol CO₂ = 0.5
Assume at RTP(25 C, 1 atm) 1 mol gas = 24 L, so volume CO₂ :
= 0.5 x 24 L
= 12 L
2. M Na₂CO₃ = 0.03 M
Volume = 1 L
mol Na₂CO₃ :
= M x V
= 0.03 x 1
= 0.03 moles
Mass Na₂CO₃(MW=106 g/mol) :
= mol x MW
= 0.03 x 106
= 3.18 g
