Answer:
B. The reaction produce a gas as a product.
Explanation:
According to the law of conservation of mass, the total mass of reactants must be equal to the total mass of products because mass is neither created nor destroyed in a chemical reaction.
The total mass of the reactants is 7 grams. The total mass of the products and the beaker is 5 grams. This means that the mass of products is less than the mass of reactants.
The only plausible explanation for this is that the reaction produced a gaseous product which escaped because the system is an open system thereby leading to a lesser measured mass of products since mass can not be created nor destroyed.
Very bad written question
C, then, D, A
Answer:
Double replacement
Explanation:
The given reaction is double replacement reaction.
CaCO₃ + 2HCl → CaCl₂ + H₂CO₃
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
while,
Synthesis reaction:
It is the reaction in which two or more simple substance react to give one or more complex product.
Decomposition:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Answer:
A star is made up of burning gases, while a comet is made up of ice, gases, rocks, and dust.
Explanation: