Answer : The time passed in years is 
Explanation :
Half-life of carbon-14 = 5730 years
First 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 disintegrate = 15.3
a - x = amount left after decay process = 14.8
Now put all the given values in above equation, we get
Therefore, the time passed in years is
Answer:
the last answer is right.
Hello!
The
dissociation reaction of HNO₃ is the following:
HNO₃ → H⁺ + NO₃⁻This is a strong acid, so the concentration of HNO₃ would be the same as the concentration of H⁺. The formula for pH is the following:
![pH=-log([H_3O^{+}])=-log(0,75M)=0,12](https://tex.z-dn.net/?f=pH%3D-log%28%5BH_3O%5E%7B%2B%7D%5D%29%3D-log%280%2C75M%29%3D0%2C12)
So, the pH would be
0,12Have a nice day!
Answer:
4 means there are four molecules of Na₂SO₃.
Explanation:
Molecule:
A molecule is the smaller particle which can exist independently.
It may be monoatomic , diatomic, triatomic etc.
For example,
Hydrogen molecule consist of two atoms H₂
Nitrogen molecule = N₂
It may be combination of atoms of different elements.
HCl, H₂SO₄,Na₂SO₃
HCl = 1 mole of hydrochloric acid or one molecules of hydrochloric acid
H₂SO₄= 1 mole of sulfuric acid or one molecule of sulfuric acid
Na₂SO₃ = 1 mole of sodium sulfite or one molecule of sodium sulfite.
4Na₂SO₃ = 4 mole of sodium sulfite or four molecule of sodium sulfite.
The coefficient before the formula indicate the total number of molecules.
