Chapter#1 chemical reactions and equations
Sure, here are 20 short questions on chemical reactions and equations along with their answers:
1:What is a chemical reaction? Answer: A chemical reaction is a process in which one or more substances (reactants) are converted into one or more different substances (products) with different properties.
2:Define a chemical equation? Answer: A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products involved using chemical formulas and coefficients.
3:What are the types of chemical reactions? Answer: The main types of chemical reactions are synthesis (combination), decomposition, single displacement (replacement), double displacement (metathesis), and combustion reactions.
4:Give an example of a synthesis reaction. Answer: 2H₂ + O₂ → 2H₂O (Hydrogen gas reacts with oxygen gas to form water)
5:What is a decomposition reaction? Answer: A decomposition reaction is a type of chemical reaction in which a compound breaks down into simpler substances.
6:Provide an example of a decomposition reaction? Answer: 2H₂O → 2H₂ + O₂ (Water decomposes into hydrogen gas and oxygen gas)
7:Define a single displacement reaction? Answer: A single displacement reaction is a chemical reaction in which one element replaces another element in a compound.
8:Give an example of a single displacement reaction? Answer: Zn + 2HCl → ZnCl₂ + H₂ (Zinc displaces hydrogen from hydrochloric acid to form zinc chloride and hydrogen gas)
9:What is a double displacement reaction? Answer: A double displacement reaction is a chemical reaction in which ions from two different compounds exchange places to form two new compounds.
10:Provide an example of a double displacement reaction? Answer: NaCl + AgNO₃ → AgCl + NaNO₃ (Sodium chloride reacts with silver nitrate to form silver chloride and sodium nitrate)
11:What is a combustion reaction? Answer: A combustion reaction is a type of chemical reaction in which a substance reacts rapidly with oxygen, often producing heat and light.
12:Give an example of a combustion reaction? Answer: 2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O (Benzene reacts with oxygen to produce carbon dioxide and water)
13:What are reactants and products in a chemical equation? Answer: Reactants are the substances that undergo a chemical change in a reaction, while products are the substances formed as a result of the chemical change.
14:Explain the law of conservation of mass? Answer: The law of conservation of mass states that the total mass of reactants in a chemical reaction is equal to the total mass of products, meaning that mass is conserved in a chemical reaction.
15:What is the difference between a chemical reaction and a physical change? Answer: In a chemical reaction, new substances with different chemical properties are formed, whereas in a physical change, the composition of the substances remains the same, and only physical properties such as shape, size, or state change.
16:Define a catalyst? Answer: A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction but is not consumed in the reaction.
17:Give an example of a catalyst? Answer: Platinum is a catalyst in the reaction between hydrogen and oxygen to form water.
18:What is a balanced chemical equation? Answer: A balanced chemical equation is one in which the number of atoms of each element is the same on both the reactant and product sides, satisfying the law of conservation of mass.
19:Explain what coefficients are in a chemical equation? Answer: Coefficients are the numbers placed before chemical formulas in a balanced chemical equation, indicating the relative amounts of reactants and products involved in the reaction.
20:How do you balance a chemical equation? Answer: To balance a chemical equation, adjust the coefficients of the reactants and products so that the number of atoms of each element is the same on both sides of the equation.
These questions cover various aspects of chemical reactions and equations and should help in understanding the fundamentals of the topic.
No comments:
Post a Comment