Correct option C
<span>Tidal power is harnessed by </span><span>building a dam across the mouth of a bay</span>
Answer:
The answer to your question is:
a) 0.069 moles of Iron
b) 0.052 moles of Oxygen
Explanation:
Data
mass Iron = 3.86 g
moles = ?
Atomic weight Fe = 56 g
Process
a) Solve it using a rule of three
56 g of Fe ---------------- 1 mol
3.86 g ---------------------- x
x = (3.86 x 1) / 56
x = 0.069 moles of Iron
b)
Balanced Equation
4Fe + 3O₂ ⇒ 2Fe₂O₃
Solve it using a rule of three
4 moles of Fe ----------------- 3 moles of O₂
0.069 moles of Fe --------- x
x = (0.069 x 3) / 4
x = 0.052 moles of Oxygen
Answer;
C7H14O2
Solution;
Isobutyl contains , oxygen, carbon and hydrogen (total mass is 1.152 g)
Mass of carbon = 12/44 × 2.726 g
= 0.743455 g
Mass of Hydrogen = 2/18 × 1.116 g
= 0.124 g
Mass of oxygen = 1.152 - (0.7435 + 0.124)
= 0.2845 g
Moles of carbon ; 0.7435/12 = 0.06196 moles
Moles of hydrogen; 0.124/1 = 0.124 moles
Moles of oxygen; 0.2845/16 = 0.01778 moles
Ratios ; 0.06196/0.01778 ; 0.124/0.01778 : 0.01778/0.01778
= 3.5 : 7.0 : 1
To make them whole numbers ; we multiply the ratios by 2 to get;
(3.5 : 7.0 : 1 )2 = 7 : 14 : 2
Thus, the empirical formula of Isobutyl propionate is C7H14O2
Calcination use temperatures roughly twice that of typical roasting. The main idea is to use high temperatures and decompose the material being heated fairly faster. Roasting tries to changes the food products by starting and supporting a number of chemical reactions within the food that results in pleasant flavor, greater availability of certain ingredients.