It is the crust, the least dense layer.
Answer: Option (1) is the correct answer.
Explanation:
Compounds are the substances which contain two or more different elements.
Similarly, water is a compound as it is made up when two hydrogen atoms combine with one oxygen atom. Compounds can be broken down with the help of chemical reactions.
Hence, the statement water can be broken down by chemical means explains why water is classified as a compound.
Answer:
The chemical reaction in which solid calcium oxide is treated liquid water is an example of Synthesis reaction. Hence, the answer is (D) Synthesis.
Explanation:
The formula of Calcium Oxide is CaO.
The formula of liquid water is H₂O.
Calcium Oxide reacts with water and forms Calcium Hydroxide. The Chemical equation is shown below.
CaO + H₂O --> Ca(OH)₂.
This is a Synthesis reaction because Ca(OH)₂ is synthesized by using Calcium Oxide and water.
The product of this reaction is calcium hydroxide, also known as slaked lime.
Thus, when calcium oxide reacts with water, slaked lime is produced.
Calcium oxide is also known as lime and is most commonly used for many purposes. It can be used for pH correction of water or for its disinfection (with excess lime).
Answer: B. 4 moles Fe and 3 moles CO2
Explanation:
write a balanced chemical reaction
that is FeO3 + 3 CO → 2 Fe + 3CO2
2 moles of Fe2O3 reacted with 3 x2=6 moles of Co to form Fe and CO2 therefore CO was in excess and Fe2O3 was limiting reagent.
use the mole ratio to determine the moles of each product.
that is the mole ratio 0f Fe2O3 : Fe is 1:2 therefore the moles of Fe = 2x2=4 moles
the mole ratio of Fe2CO3 : CO2 is 1: 3 therefore the moles of Co2 = 2 x3 = 6 moles
