Because the space is ultimate thermos.
Answer : The correct answer is a) an exothermic reaction that releases energy.
Combustion reaction is generally referred as burning or when hydrocarbon reaction with oxygen to produce carbon dioxide and water . Combustion reaction releases energy. Example :
CH₄ + O₂ → CO₂ + H₂O + Energy or heat .
The reaction which releases energy or heat are known as Exothermic reactions .
Since it says hot dogs and hamburgers are cooked means they are undergoing combustion chemical reaction and so they are exothermic reactions. So option a) an exothermic reaction which releases energy is correct .
S + 2e⁻ → S²⁻ (sulfur will gain electrons)
Mg - 2e⁻ → Mg²⁺ (magnesium will lose electrons)
Magnesium is a metal which tends to give electrons which are received by the sulfur, which is a nonmetal and tends to gain electrons.
The given chemical reaction is between calcium carbonate and hydrochloric acid to produce calcium chloride, carbon dioxide and water. This reaction can be represented as,
When the concentration of the reactants is increased, the number of collisions that take place between the reactant molecules increases. This speeds up the reaction. Therefore, when the concentration of HCl is doubled as long as there is enough calcium carbonate to react with HCl, the number of effective collisions giving products increases, this causes the rate of forward reaction to increase.
