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:
Length of sides of poster = 2 Ft
Length of sides of box = 2.41 Ft
Since the box has a longer side than the poster, the poster will lie flat when placed in the box.
Step-by-step explanation:
In order to determine if the poster will lie flat in the box or not, we will determine the length of the sides of the poster and the box, if the length of the side of the square poster is smaller than that of the box, it will lie flat. This is calculated as follows:
Area of poster = 4 square feet
Area of poster = (Length)²
4 = (Length)²
∴ Length = √(4)
Length of poster = 2 Ft
Volume of box = 14 cubic feet
Volume of box = (Length)³
14 = (Length)³
∴ Length = ∛(14)
Length = 2.41 Ft
∴ Length of sides of poster = 2 Ft
Length of sides of box = 2.41 Ft
Since the box has a longer side than the poster, the poster will lie flat when placed in the box.
Answer:
= x(a+b)(a-b) . x(b+c)(b-c) .x(c+a)(c-a)
Answer:
B.
Step-by-step explanation: Because when you count them down to 3/5 It's more in the negative.