Combination Reaction

Q.

Which among the following changes are exothermic or endothermic in nature?

(b)Dilution of sulfuric acid

Q. Formation of water from hydrogen and oxygen is an example of _________ reaction.

1. decomposition
2. displacement
3. precipitation
4. combination

Q.

The burning of Magnesium ribbon in the air is an example of _______.

Q.

Give one example of an oxidation-reduction reaction which is also :

(a) a combination reaction

(b) a displacement reaction

Q.

$50\mathrm{g}$ of ${\mathrm{CaCO}}_3$ is allowed to react with$70\mathrm{g}$ of ${\mathrm{H}}_3{\mathrm{PO}}_4$_.

Calculate:

(i) Amount of ${\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2$formed

(ii) Amount of unreacted reagent

Q.

(a) Define a combination reaction.

(b) Give one example of a combination reaction which is also exothermic.

(c) Give one example of a combination reaction which is also endothermic.

Q. Burning of coal is a combination reaction.

1. True
2. False

Q.

What kind of reaction is slaking of lime?

Q.

When hydrogen burns in oxygen, water is formed and when water is electrolysed, then hydrogen and oxygen are produced. What type of reaction takes place :

(a) in the first case ?

(b) in the second case ?

Q.

Calcium carbonate reacts with dilute hydrochloric acid to form calcium chloride. In this reaction, carbon dioxide gas evolved with brisk effervescence.

1. True
2. False

Q.

What do you observe when water is added to quick lime?

Q.

Can a combination reaction be a redox reaction? Give an example in support of your answer.

Q.

Identify the compound X on the basis of the reactions given below. Also, write the name and chemical formulae of A, B and C.

Q.

Define a combination reaction. Give one example of a combination reaction which is also exothermic. [2 MARKS]

Q. Magnesium ribbon keeps on burning in atmosphere of nitrogen to form _____________ and this type of reaction is called ________

1. magnesium nitride, decomposition reaction
2. magnesium nitride, combination reaction
3. magnesium nitrite, decomposition reaction
4. magnesium nitrite, combustion reaction
   

Q.

Write the equation when Sodium hydroxide is added to a solution of Ferric chloride.

Q.

A dry pellet of a common base B, when kept in the open absorbs moisture and turns sticky. The compound is also a by-product of the chloralkali process. Identify B. What type of reaction occurs when B is treated with an acidic oxide? Write a balanced chemical equation for one such solution.

Q.

What is a skeleton equation?

Q.

What type of chemical reactions take place when :

(a) a magnesium wire is burnt in air ?

(b) lime-stone is heated ?

(c) silver bromide is exposed to sunlight ?

(d) electricity is passed through water ?

(e) ammonia and hydrogen chloride are mixed ?

Q.

While cooking heat is produced also so why it is endo thermic reaction???

Q. Which of the following reactions involves the combination of two elements?

1. $CaO+C{O}_2\to CaC{O}_3$
2. $4Na+O_2\to 2N{a}_{2}O$
3. $2S{O}_2+O_2\to 2S{O}_3$
4. $N{H}_3+HCl\to N{H}_{4}Cl$

Q. Question 9
What does one mean by exothermic and endothermic reactions? Give examples.

Q.

State one industrial application of reduction process.

Q.

What type of chemical reactions are represented by the following equations ?

(i) $A+BC⟶AC+B$

(ii) $A+B⟶C$

(iii) $X⟶Y+Z$

(iv) $PQ+RS⟶PS+RQ$

(v) $A_2{O}_3+2B⟶B_2{O}_3+2A$

Q.

How do synthesis reactions differ from combination reactions?

Q. $\text{C(s)}+{\text{O}}_2\text{(g)}\to {\text{CO}}_2\text{(g)}$

Identify the type of chemical reaction.

1. Double displacement reaction
2. Displacement reaction
3. Decomposition reaction
4. Combination reaction

Q. A shiny brown coloured metal ‘X’ on heating in air becomes black in colour. The element 'X' and black coloured compound are ___ and ___ respectively.

1. copper, copper oxide
2. silver, silver oxide
3. iron, iron oxide
   
4. magnesium, magnesium oxide

Q.

How would you separate a mixture of benzene and water?

Q.

The following is a list of methods for the preparation of salts.

A - direct combination of two elements.

B - reaction of a dilute acid with a metal.

C - reaction of a dilute acid with an insoluble base.

D - titration of a dilute acid with a solution of soluble base.

E - reaction of two solutions of salts to form a precipitate.

Choose from the above list A to E, the best method of preparing the following salts by giving a suitable equation in each case :

1. Anhydrous ferric chloride, 2. Lead chloride,

3. Sodium sulphate, 4. Copper sulphate.

Q.

Write the balanced equation of manganese$\left(IV\right)$ oxide and concentrated hydrochloric acid?