Answer:
B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HC
Explanation:
A balanced reaction has the same number of atoms in the both sides of the reaction. In the options:
A. CaCl₂ + H₂CO₃ → 2CaCO₃ + HCI
In this reaction there is 1 Ca in reactants and 2 in products -<em>The reaction is unbalanced-</em>
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<h3>B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HCl
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There is 1 Ca is both sides, 2Cl, 2H, 1C and 3 Oxygens -<em>The reaction is balanced</em>
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C. CaCl₂ + 2H₂CO₃ → CaCO₃ + HCI
There is 1 Ca in both sides but 2Cl in reactants and 1 in Cl -<em>The reaction is unbalanced-</em>
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D. 2CaCl₂ + H₂CO₃ →CaCO₃ + HCI
There are 2 Ca in reactants and 1 in Ca -<em>The reaction is unbalanced-</em>
It's 18 (the same as the number of protons:)
<span>It is the valence orbit that controls the electrical properties of the atom. The valence electron is referred to as a "free electron.' Valence electrons have the highest energy of all electrons in an atom; they are also the most reactive, meaning they are usually the electrons involved in bonding. When silicon atoms combine to form a solid, they arrange themselves into an orderly pattern called a crystal.</span>
Answer : The change in entropy is 
Explanation :
Formula used :
where,
= change in entropy = ?
m = mass of water = 1.00 kg
= heat of vaporization of water = 
T = temperature = 
Now put all the given values in the above formula, we get:
Therefore, the change in entropy is
Heat capacity of aluminium = 0.900 J/g°C
While heat capacity of water = 4.186 J/g°C
Heat = heat gained by water + heat gained by aluminium
Heat gained by water = 100 × 4.186 × 30.5
= 12767.3 Joules
Heat gained by aluminium = 15 × 0.9 × 30.5
= 411.75 Joules
Heat required = 13179.05 Joules or 13.179 kJoules
