Answer:
12.33 cal/sec
Explanation:
As we know,
1 Kcal = 1000 cal
So,
0.74 Kcal = X cal
Solving for X,
X = (0.74 Kcal × 1000 cal) ÷ 1 Kcal
X = 740 cal
Also we know that,
1 Minute = 60 Seconds
Therefore, in order to derive cal/sec unit replace 0.74 Kcal by 740 cal and 1 min by 60 sec in given unit as,
= 740 cal / 60 sec
= 12.33 cal/sec
2Ca + O2 = 2CaO
First, determine which is the excess reactant
72.5 g Ca (1 mol) =1.8089725036
(40.078 g)
65 g O2 (1 mol) =2.0313769611
(15.999g × 2)
Since the ratio of to O2 is 2:1 in the balanced reaction, divide Ca's molar mass by 2 to get 0.9044862518. this isn't necessary because Ca is already obviously the limiting reactant. therefore, O2 is the excess reactant.
Now do the stoichiometry
72.5 g Ca (1 mol Ca) (1 mol O2)
(40.078 g Ca)(2 mol Ca)(31.998g O2)
=0.0282669621 g of O2 left over
<span> reason is that there is no land to slow down the wind. Also, wind is caused by differences in air pressure</span>
If you mean hydrate as in <em>MgSO4 · 7H2O, </em>then simply find the molar mass of each element you see.
For the example above, that means you would add the molar mass (found on the periodic table) of Mg, then S, then 4(O), 14(H), and 7(O).
The results would be your molar mass for the hydrate.
I hope this is what you meant by your question!
Your answer is going to be B. at the focal point of the lens. :)