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:
Light travels in a straight line until it strikes an object.
As white light passes through a prism , it bends and separates into different colors
Answer:
3.91 minutes
Explanation:
Given that:
Biacetyl breakdown with a half life of 9.0 min after undergoing first-order reaction;
As we known that the half-life for first order is:

where;
k = constant
The formula can be re-written as:



Let the initial amount of butter flavor in the food be
= 100%
Also, the amount of butter flavor retained at 200°C
= 74%
The rate constant 
To determine how long can the food be heated at this temperature and retain 74% of its buttery flavor; we use the formula:


Substituting our values; we have:

t = 3.91 minutes
∵ The time needed for the food to be heated at this temperature and retain 74% of its buttery flavor is 3.91 minutes
Convert temperature to Kelvin
Convert vol to L
Apply Charles law
- V1T_2=V2T_1
- 0.4(400)=498V_2
- 160=498V_2
- V_2=0.32L=320mL