John planned to pack 1/2 of his books in the morning and the rest in the afternoon. If he packed only 3/4 as many as he packed i
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Answer:
The angles are 26 and 64
Step-by-step explanation:
When two angles are complementary, what this means is that the add up to 90 degrees
Now, let’s say one of the angles is x, the other angle is 12 more than twice it; mathematically that would be 2x + 12
Since they add up to be 90, we have
x + 2x + 12 = 90
3x + 12 = 90
3x = 90-12
3x = 78
x = 78/3
x = 26
The other angle is 2x + 12 = 2(26) + 12 = 52 + 12 = 64
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