There are several various of expressing concentration. For instance, mass percent, volume percent, Molarity, Normality, Molality, etc.
In present case, weight of solute and solvent are given, so it will be convenient to express concentration in terms of mass percent.
Given: weight of solute (Ca2+) = 8500 g
weight of solvent (water) = 490 g.
Therefore, mass of solution = 8500 + 490 = 8990 g
Now, mass percent =

=

= 94.55 %
Answer: Concentration of calcium ions is in this solution is 94.55 % (w/W)
The gas, 2 mol of H2, occupies the highest volume at STP since at STP the volume of this gas is approximately 44.8 mol as compared to other options this has the greatest amount.
Wastes
Fuel
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Gas
Toxic chemicals
Answer:
0.2M NaOh
Explanation:
there are 0.2 mol of NaOH in 8.0 g. (8.0/40) =0.2. Molarity = mol/L = 0.2M.