B is the answer i hope it helps i
1.326 grams of NH3 are required to produce 4.65 g of HF.
Step-by-step explanation:
Balanced chemical reaction is written first to know the number of moles taking part in original reaction.
NH3 +3 F2 ⇒3 HF + NF3
Given:
mass of HF = 4.65
First the number of moles of HF in 4.65 grams is calculated by using the formula:
number of moles (n) = 
atomic mass of HF = 20 grams/mole
putting the values in the above equation number of moles can be found.
n = 
= 0.235 moles of HF are given.
From the equation it can be said that:
1 mole of NH3 reacts to form 3 moles of HF
so, x moles of NH3 would react to form 0.235 moles of HF
= 
3x = 0.235
x = 
x = 0.078 moles of NH3 is required.
The moles are converted to mass by applying the formula:
mass = atomic mass X number of moles (atomic mass of NH3 = 17 grams/mole)
putting the values in the formula
mass = 17 X 0.078
mass = 1.326 grams
Answer:
13,26,39,52,65,78 are the multiples 13 and 1 are the all of the factors
We know that the total volume of the solution is 187 cubic feet.
187=3x+8x
187=11x
17=x
Now we know that the ratio 3 to 8 is 51 to 136.
Double check, (3*17)+(8*17)=187.
I'm not sure which part of the ratio is water, but knowing this information, you should be able to solve it. I believe it may be this:
The total volume of milk is 51. If the rest of the solution is water, then 187-51=136.
F(2)=42(2)-100
f(2)= -16
f(2)/-16= -8