Answer:
4.22 × 10 ⁻²² mol
Explanation:
Given data:
Number of molecules of bromine = 254 molecules
Number of moles = ?
Solution:
1 mole = 6.02 × 10 ²³ molecules
254 molecules × 1 mol / 6.02 × 10 ²³ molecules
42.2 × 10 ⁻²³ mol
4.22 × 10 ⁻²² mol
Answer:
C
Explanation:
1mL = 1cm
3 * 1 = 3cm³
We use "³" because we are working with units that represent volume.
Best of Luck!
the answer is thermal energy
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
