NaOH + _________________ __________________ + H2Oii. 2HCl + __________________ CaCl2 + _______________ + CO2iii. CaCO3 + H2SO4 ________________________

It appears you are looking for the products of certain chemical reactions involving the reactants given. Here's how you can fill in the blanks for each reaction step by step:

1. Break Down the Problem

Each blank represents a product formed in the chemical reaction. We can analyze each reaction one by one.

2. Relevant Concepts

• Neutralization Reaction: When a strong base (like NaOH) reacts with a strong acid (like HCl), it produces a salt and water.
• Reactivity of Calcium Compounds: CaCl2 is formed when calcium carbonate (CaCO3) reacts with an acid like H2SO4.
• Decomposition Reaction: Calcium carbonate reacts with sulfuric acid to produce CO2 gas, water, and calcium sulfate.

3. Analysis and Detail

• i. NaOH + _________ → _________ + H2O

  Since NaOH (sodium hydroxide) reacts with an acid like HCl (hydrochloric acid): $\text{NaOH + HCl } \rightarrow \text{ NaCl + H}_2\text{O}$ So, it fills as: $\text{NaOH + HCl } \rightarrow \text{NaCl + H}_2\text{O}$

• ii. 2HCl + _________ → CaCl2 + _________ + CO2

  Here, if we consider CaCO3, the balanced reaction looks like this: $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$ So, it fills as: $2\text{HCl + CaCO}_3 \rightarrow \text{CaCl}_2 + H_2O + CO_2$

• iii. CaCO3 + H2SO4 → __________

  The reaction here also involves CaCO3 and H2SO4 (sulfuric acid): $\text{CaCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + \text{H}_2\text{O} + \text{CO}_2$ So, it fills as: $\text{CaCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + H_2O + CO_2$

4. Verify and Summarize

Now let's summarize the complete reactions:

1. First Reaction: $\text{NaOH + HCl} \rightarrow \text{NaCl + H}_2\text{O}$

2. Second Reaction: $2\text{HCl} + \text{CaCO}_3 \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$

3. Third Reaction: $\text{CaCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + \text{H}_2\text{O} + \text{CO}_2$

Final Answer

1. i. NaCl
2. ii. CaCO3
3. ii. H2O
4. iii. CaSO4

The complete reactions would be:

i. NaOH + HCl → NaCl + H2O

ii. 2HCl + CaCO3 → CaCl2 + H2O + CO2

iii. CaCO3 + H2SO4 → CaSO4 + H2O + CO2