13.
balance the equation.
ca(no3)2 + na2co, → caco3 + na no3

Ca(NO3)2 + Na2CO3 -> CaCO3 + 2NaNO3

Explanation:

As Calcium ion (Ca) has a valency of +2, it requires an anion with equivalent valency of -2. Nitrate ion (NO3) has a valency of -1 so it needs 2 molecules of it to satisfy the Calcium's +2 valency.

Carbonate (CO3) has -2 valency, so it replaces the 2 NO3 molecules by 1 of itself and bonds to Ca.

Sodium (Na) has +1 valency, so it is satisfied by 1 molecule of NO3 but there are 2 molecules of both Na and NO3. Therefore, we attach the stoichiometric coefficient of 2 to NaNO3.

hurricanes form in warm water

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

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