Answer:
Mario uses a hot plate to heat a beaker of 50mL of water. He used a thermometer to measure the
temperature of the water. The water in the beaker began to boil when it reached the temperature of
100'C. If Mario completes the same experiment with 25mL of water, what would happen to the boiling
point?
a) The water will not reach a boil.
b) The boiling point of water will increase.
c) The boiling point of water will decrease.
d) The boiling point of water will stay the same.
Explanation:
Hope this helps! 159.2086<span>Have a Good Day!</span>
<u>Answer:</u> The half life of the sample of silver-112 is 3.303 hours.
<u>Explanation:</u>
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
![k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%20%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 1.52 hrs
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:
To calculate the half life period of first order reaction, we use the equation:
where,
= half life period of first order reaction = ?
k = rate constant = 
Putting values in above equation, we get:
Hence, the half life of the sample of silver-112 is 3.303 hours.
First calculate for the molar mass of the given formula unit, CaCO₃. This can be done by adding up the product when the number of atom is multiplied to its individual molar mass as shown below.
molar mass of CaCO₃ = (1 mol Ca)(40 g Ca/mol Ca) + (1 mol C)(12 g of C/1 mol of C) + (3 mols of O)(16 g O/1 mol O) = 100 g/mol of CaCO₃
Then, divide the given amount of substance by the calculated molar mass.
number of moles = (20 g)(1 mol of CaCO₃/100 g)
number of moles = 0.2 moles of CaCO₃
<em>Answer: 0.2 moles</em>
