Answer:
The change was physical, meaning it went from liquid to solid, or the other way around.
Explanation:
Answer:
1) 0.0625 g.
2) 0.0125 g.
Explanation:
<em>1) A solution of NaOH has a concentration of 25.00% by mass. What mass of NaOH is present in 0.250 g of this solution?</em>
mass% of NaOH = [(mass of NaOH)/(mass of solution)] x 100.
mass% of NaOH = 25.0%, mass of NaOH = ??? g, mass of solution = 0.250 g.
∴ mass of NaOH = (mass% of NaOH)(mass of solution)/100 = (25.0%)(0.250 g)/100 = 0.0625 g.
<em>2) What mass of NaOH must be added to the solution to increase the concentration to 30.00% by mass?</em>
We can use the relation:
mass% of NaOH = [(mass of NaOH)/(mass of solution)] x 100.
mass% of NaOH = 30.0%, mass of NaOH = ??? g, mass of solution = 0.250 g.
∴ mass of NaOH = (mass% of NaOH)(mass of solution)/100 = (30.0%)(0.250 g)/100 = 0.075 g.
∴ The mass of NaOH should be added = 0.075 - 0.0625 = 0.0125 g.
I think it’s ten because it’s becoming darket
Answer:
24%
Explanation:
From the question, the limiting reactant is H2S.
The reaction equation is;
2H2S + O2 → 2S + 2H2O
Number of moles of H2S reacted = 22g/34 g/mol = 0.647 moles
According to the reaction equation;
2 moles of H2S yields 2 moles of sulphur
0.647 moles of H2S yields 0.647 moles of sulphur
So;
Theoretical yield of sulphur = 0.647 moles * 32 g/mol = 20.7 g
Actual yield = 5 g
% yield = actual yield/theoretical yield * 100
% yield =5 g/20.7 g * 100
% yield = 24%
Answer:
Explanation:
substance (as an acid or salt) that when dissolved (as in water) conducts an electric current.
