B. Statements given below are incorrect. Write
the correct statements
1. While writing a chemical equation, one need
not to know whether the reaction takes
place between two or more reactants
2. A balanced chemical equation consists of
formulae of reactants connected by a(+) plus sign
and is equal to (=) followed by the formulae of
products, connected by (+) plus sign
3. During a physical change a large amount of
heat energy absorbed or given out.
4. On strong heating ammonium chloride
decomposes into nitrogen, oxygen and
chlorine gas.
5. A lot of heat is needed to start the reaction
between sodium hydroxide and hydrochloric
acid.
Answers
Answer:
1. While writing a chemical equation, one need not to know whether the reaction takes place between two or more reactants
Correction : While writing a chemical equation, one must know whether the reaction takes place between two or more reactants.
2. A balanced chemical equation consists of formulae of reactants connected by a(+) plus sign and is equal to (=) followed by the formulae of products, connected by (+) plus sign.
Correction : A balanced chemical equation consists of formulae of reactants connected by a(+) plus sign and is equal to (=) followed by the formulae of products, connected by (+) plus sign. The number of atoms of an element are equal in reactants as well as products.
3. During a physical change a large amount of heat energy absorbed or given out.
Correction: During a physical change a small amount of heat energy absorbed or given out.
4. On strong heating ammonium chloride decomposes into nitrogen, oxygen and chlorine gas.
Correction: On strong heating ammonium chloride decomposes into ammonia and HCl gas.
5. A lot of heat is needed to start the reaction between sodium hydroxide and hydrochloric acid.
Correction: No heat is needed to start the reaction between sodium hydroxide and hydrochloric acid.
Answer:
1. one need to know whether the reaction takes place or not
2.A balanced chemical equations consist of reactants and products balanced at both sides
3.yes
4.it decomposes anomia and hydrogen dichloride
5.yes