Alka-seltzer in an antacid that contains a mixture of sodium bicarbonate and citric acid. When the tablet is dissolved in water, the reactants which are in solid form in tablet become aqueous and react with each other.
During this reaction, Carbon Dioxide gas is evolved which causes the reaction mixture to fizz. The equation is given below.
Rate of the above reaction is affected by the Temperature.
As the temperature increases , the rate of the reaction increases. This happens because at higher temperature, the collisions between reacting species are more which result in formation of product in less time. This increases the rate of reaction.
We have been given equal volumes of water for each beaker. But the temperature of beaker c is 80°C which is the highest temperature. That means the reaction in beaker c is fastest.
Whereas beaker a is at lowest temperature (30°C) , therefore the reaction in beaker a would be slowest .
Therefore the answer that correctly orders the reaction rates from fastest to slowest reaction is beaker c > beaker b > beaker a