Answer:
The half life time of first order reaction is 1.3 sec
Explanation:
Given:
First order rate constant 
Initial concentration 
M
From the formula of first order half life time,
So half life time is given by,
sec
Therefore, the half life time of first order reaction is 1.3 sec.
Answer:
34.8 moles of CO₂ are produced
Explanation:
This is the reaction:
1C₅H₁₂ + 8O₂ → 6H₂O + 5CO₂
Ratio is 1:5. We make a rule of three
1 mol of pentane can produce 5 moles of CO₂
Then, 6.96 moles of pentane may produce (6.96 .5) / 1 = 34.8 moles
Concentration of a solution can be expressed in terms of molarity and molality
Molarity is the number of moles of solute in a liter of a solution.
Molarity (M) = Moles of solute/Volume(litres) of solution
Molality is the number of moles of solute in one kg of the solution
Molality (m) = Moles of solute/Mass (kg) of solution
Therefore if the volume or the mass of the solution is changed this would affect the concentration.
In addition, volume is a quantity which depends on temperature. However, mass is independent of temperature. Therefore any changes in temperature, can also bring about a change in the molarity of the solution.
Answer:
0.0432 M H2SO4
Explanation:
First, we want to find the moles of MNaOH used. We know that Molarity x Liters = moles. 0.160M x 0.0210L = 0.00336 moles MNaOH
to find the moles of H2SO4, we can use a mol ratio.
0.00336mol MNaOH x (1Mol H2SO4 /2mol MNaOH)
= 0. 00168 mol H2SO4
I found the mol ratio by looking at the coefficients in front of the molecules I knew(MNaOH) and the molecule I needed to find(H2SO4)
then, to find Molarity, we do mol/Liters
0.00168 mol/ 0.0388L =. 0.0432 M H2SO4
You can convert mL to L by dividing by 1000
the significant figures of this problem is 3, so my final answer will also have 3 sig figs.
