Given that,
A car uses a litre of petrol to travel 4 km.
To find,
How many litres will it use to travel 32 kilometres.
Solution,
We have,
1 litre = 4 km
or
1 km = (1/4) litre
Let it will use x litres to travel 32 km.
32 km = (32/4) litres
= 8 litres
Hence, 8 litres it will use to travel 32 km.
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:
(-9+√17)/8
Step-by-step explanation:
its an example of quadratic
Answer: Number of ways
Step-by-step explanation:
When there is no replacement , we use combination to find the number of ways to choose things.
Number of ways to choose r things out of ( with out replacement) =
The number of ways to choose 8 things =
Hence, Number of ways