Answer:
An exothermic reaction is going to produce energy.
Explanation:
rAn exothermic reaction is going to release energy meaning that your ending product will be negative. However if it is an endothermic reaction, it is going to absorb energy/requires energy, and will have an ending product that is positive.
Answer:
19.4 g of alum, will be its theoretical yield
Explanation:
The reaction is:
2 Al + 2 KOH + 4 H₂SO₄ + 22H₂O → 3H₂ + 2KAl(SO₄)₂•12H₂O
Let's determine the amount of acid.
M are the moles contained in 1 L of solution or it can be mmoles that are contained in 1 mL of solution
M = mmol /mL
M . mL = mmol
We replace: 8.3 mL . 9.9 M = 82.17 mmoles
We convert to moles: 82.17 mmol . 1 mol / 1000mmol = 0.082 moles
Ratio is 4:2
4 moles of sulfuric acid can make 2 moles of alum
By the way, 0.082 moles of acid may produce ( 0.082 . 2) /4 = 0.041085 moles.
We convert moles to mass:
Molar mass of alum is: 473.52 g/mol.
0.041085 moles . 473.52 g/mol = 19.4 g
Answer:
0.16 moles of Carbon
Explanation:
The balanced reaction equation:
+ → + ↑
The mole ratio of Carbon to Iron is 3 : 4 (since Fe2O3 is in excess)
i.e 3 moles of C produces 4 moles of Fe.
If 1 mole of Fe - 55.8g of Fe
? moles - 11.6g of Fe
= = 0.208 moles
But 3 moles of C - 4 moles of Fe
? moles of C - 0.208 moles of Fe
= = 0.16 moles of carbon.
I hope this explanation was clear and useful.
Answer:
= 28.745 g
Explanation:
Half life is the time taken by a radioactive element to decay by half the original amount.
Therefore;
New mass = Original mass × (1/2)^n
Where n is the number of half lives, in this case, n = 20/5.27 = 3.795
Therefore;
New mass = 399 g × (1/2)^3.795
<u> = 28.745 g</u>