Answer :
The parent and daughter concentrations (in percentages) is, 60 % and 40 % respectively.
The age of rock is 
Explanation :
First we have to calculate the parent and daughter concentrations (in percentages).

and,

As we know that, the half-life of uranium-238 =
years
Now we have to calculate the rate constant, we use the formula :



Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant = 3 g
a - x = amount left after decay process = 1.8 g
Now put all the given values in above equation, we get


Therefore, the age of rock is 
Answer:
0.22 g of CO2 were produced.
Explanation:
First, let's represent what is happening with an hypothetical chemical equation just to have a clearer vision of the presented process:
CaCO3 (aq) + 2 HAc (aq) → CaAc2 (aq) + H2O (l] + CO2 (g)
We have a tablet that has CaCO3 as the active ingredient that when combined with an acid, in this case represented as HAc, reacts producing a Calcium salt, water and carbon dioxide that will leave the solution as gas.
Having said that, we know that the initial mass of the reactants will have to maintain during the chemical reaction, or what is the same, the quantity of matter during the process will not change. So, if we have a tablet that weighs 0.853 g and we add an acid solution of 56.519 g, then we have that the initial mass of the reactants will be:
0.853 g from tablet + 56.519 g from acid solution = 57.372 g
This amount of matter should be the same after the reaction, but we know that the CO2 gas will leave the solution once it's formed, so considering that the resulting solution weighs 57.152 g we could calculate the mass of CO2 produced:
57.372 g of initial mass - 57.152 g of resulting solution = 0.22 g of CO2 that left the aqueous solution as gas.
Henry's Law is written in equation as:
C = kP
where
C is the concentration
k is the Henry's law constant
P is the partial pressure
This law is applied to soluble gases in liquids. At a certain temperature, there is a specific value of the Henry's Law constant. The C represents the solubility. Hence, we solve for C.
C = (<span>6.26×10</span>⁻⁴ <span>mol/(L⋅atm))*(2.85 atm)
C = 0.0017841 mol/L</span>