Answer:
2 a
element pure form cannot broken down
3 b
Chemical change chemical R×N
(R×N = reaction)
4c homogeneous solution
Yield = Yield (reaction yield): A measure of a chemical reaction's efficiency, as a ratio of moles of product to moles of reactant. Usually expressed as a percentage. % Yield = Moles of product.
Explanation:
Given concentration of NaCl=15%
Means ,
In every 100g of Solution 15g of NaCl is present .
Now
So ,
<u>37.5g of NaCl present in 250g of solution.</u>
Answer:
0.84 moles of oxygen are required.
Explanation:
Given data:
Mass of CO₂ produced = 37.15 g
Number of moles of oxygen = ?
Solution:
Chemical equation:
C + O₂ → CO₂
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 37.15 g/ 44 g/mol
Number of moles = 0.84 mol
Now we will compare the moles of oxygen and carbon dioxide.
CO₂ : O₂
1 : 1
0.84 : 0.84
0.84 moles of oxygen are required.
500 mg in g :
1 g ----------- 1000 mg
? -------------- 500 mg
500 x 1 / 1000 => 0.5 g
total mass:
50 g + 0.5 g + 0.1 g => 50.6 g
hope this helps!
