Answer:
New volume is 14.35 mL
Explanation:
When a system of a gas keeps on constant its temperature and number of moles, the pressure is modified indirectly proportional to the volume:
Pressure increased → Volume decreased
Pressure decreased → Volume increased.
The relation you have to apply is: P₁ . V₁ = P₂. V₂
1.23 atm . 35 mL = 3 atm . V₂
(1.23 atm . 35 mL / 3 atm) = V₂
V₂ = 14.35 mL
The volume of CO₂ at STP = 2.8 L
<h3>
Further explanation
</h3>
Given
21 gram of sodium hydrogen carbonate-NaHCO₃
Required
Volume of CO₂
Solution
The decomposition of sodium bicarbonate into sodium carbonate, carbon dioxide, and water :
2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)
mol of NaHCO₃ :
= mass : MW NaHCO₃
= 21 g : 84 g/mol
= 0.25
From the equation, mol ratio of NaHCO₃(s) :CO₂(g) = 2 : 1, so mol CO₂ :
= 1/2 x mol NaHCO₃
= 1/2 x 0.25
= 0.125
At STP, 1 mol gas = 22.4 L, so for 0.125 mol :
= 0.125 x 22.4 L
= 2.8 L
The mass percentage of Na in NaCl is 39.0%
This means that if there's 100 mg of NaCl , 39 mg of the compound is Na.
For compound to contain 39 mg Na - 100 mg of NaCl should be present.
Therefore for the compound to contain 400 mg - 100/39 x 400 - 1025.6 mg
The mass of NaCl present should be 1.026 g
They share four electrons, two from each oxygen atom