The answer is C I got it right so hope it helped ;)
Answer:The law of conservation of matter says that matter cannot be created or destroyed. In chemical equations, the number of atoms of each element in the reactants must be the same as the number of atoms of each element in the products. ... There are two oxygen atoms in the reactants and two atoms of oxygen in the product.
Explanation:
I believe it is Sodium. I could be wrong though.
A) in pure water :
by using ICE table:
According to the reaction equation:
BaCrO4(s) → Ba^2+(aq) + CrO4^2-(aq)
initial 0 0
change +X +X
Equ X X
when Ksp = [Ba^2+][CrO4^2-]
by substitution:
2.1 x 10^-10 = X* X
∴X = √2.1 x 10*-10
∴X = 1.4 x 10^-5
∴ the solubility = X = 1.4 X 10^-5
B) In 1.6 x 10^-3 m Na2CrO4
by using ICE table:
According to the reaction equation:
BaCrO4(s) → Ba^2+(aq) + CrO4^2-(aq)
initial 0 0.0016
Change +X +X
Equ X X+0.0016
when Ksp = [Ba^2+][CrO4^2-]
by substitution:
2.1 x 10^-10 = X*(X+0.0016) by solving for X
∴ X = 1.3 x 10^-7
∴ solubility =X = 1.3 x 10^-7
Answer:

Explanation:
Any gas at standard temperature and pressure (STP) has a volume of 22.4 liters per mole or 22.4 L/mol. We can create a proportion with this value.

Multiply both sides of the equation by 6.8 moles of krypton.

The units of moles of krypton will cancel.

The denominator of 1 can be ignored, so this becomes a simple multiplication problem.


If we round to the nearest whole number, the 3 in the tenths place tells us to leave the 2 in the ones place.

6.8 moles of krypton gas at standard temperature and pressure is equal to <u>152 liters</u>.