Answer:
1.65hr
Explanation:
Given parameters:
Number of labs = 5 labs
Time taken = 3 minutes
Unknown:
Time taken in hours to grade 165 labs = ?
Solution:
Let us find the rate of the teacher;
Rate = 
Insert the parameters and solve;
Rate = 
= 1.67labs/min
Now;
Time to grade 165 labs = 
Time to grade 165 labs = 
= 98.8min
Since;
60min = 1hr
98.8min = 
= 1.65hr
The answer is A because the other don’t match
Mathematical formula of Ideal Gas Law is PV=nRT
where: P-pressure,
V-volume
n-number of moles; m/MW
T-Temperature
m-mass
d-density ; m/V
MW-Molecular Weight
R- Ideal Gas constant. If the units of P,V,n & T are atm, L, mol & K respectively, the value of R is 0.0821 L x atm / K x mol
Substituting the definitions to the original Gas equation becomes:
d= P x MW / (RxT)
Solution : d= .90atm x 28 g/mol (CO) / 0.0821Lxatm / mol x K x 323 K
d = 25.2 g / 26000 mL
d = .0.00096 g/mL is the density of CO under the new conditions
Make sure all units are consistent. Convert ml to L first. (500ml = 0.5L). Then divide the mole by the volume which would result to 1.6*10^-4mol/L. This can also be expressed as interms of molarity (M). 1 M = 1 mol/L hence the final answer is <span>1.6*10^-4 M. </span>
