Answer: 40.1%
Explanation: The mass of calcium in this compound is equal to 40.1 grams because there's one atom of calcium present and calcium has an atomic mass of 40.1 . The molar mass of the compound is 100.1 grams. Using the handy equation above, we get: Mass percent = 40.1 g Ca⁄100.1 g CaCO3 × 100% = 40.1% Ca.
Answer:
a and b are correct
Explanation:
This because both are aqueous solutions,therefore, identity of solvent is same that is water.
And because both solutions are non electrolyte they would not ionize in solution, and for the same concentration, the freezing point of both solution would also be same. Since depression in freezing point is a colligative property this means that it depends on number of solute particles not nature of particles
.
Hence answer is that their freezing points and Identity of the solvent shall remain the same.
Answer:
Explanation:
= Density of helium at stp = 0.179 g/L
M = Molar mass of helium = 4 g/mol
V = Volume of helium = 8.4 L
Mass of helium
Number of moles is given by
The number of moles of helium in the balloon is 
Size of a sodium ion is smaller than a sodium atom.
Mg + HNO3 -> Mg(NO3)2 + H2
On reactants side:
Mg=1
H=1
N=1
O=3
On products side:
Mg=1
H=2
N=2
O=6 (3×2)
Therefore to balance the equation, we must add 2 to HNO3 on the reactants side...
Mg + 2HNO3 -> Mg(NO3)2 + H2
Reactants:
Mg=1
H=2
N=2
O=6
Therefore, it's balanced.
