Answer:
84.8%
Explanation:
Step 1: Given data
Bob measured out 1.60 g of Na. He forms NaCl according to the following equation.
Na + 1/2 Cl₂ ⇒ NaCl
According to this equation, he calculates that 1.60 g of sodium should produce 4.07 g of NaCl, which is the theoretical yield. However, he carries out the experiment and only makes 3.45 g of NaCl, which is the real yield.
Step 2: Calculate the percent yield.
We will use the following expression.
%yield = real yield / theoretical yield × 100%
%yield = 3.45 g / 4.07 g × 100% = 84.8%
 
        
             
        
        
        
<span>The answer is synthesis. This is a kind of reaction in which numerous reactants mix to make a single product. Synthesis responses discharge energy in the way of heat and light, so they are exothermic. An instance of a synthesis reaction is the creation of water from hydrogen and oxygen.</span>
        
                    
             
        
        
        
The reason why the reaction written on the picture can be classified as a synthesis reaction is :
the reaction shows one compound that formed from two compounds 
hope this helps
        
             
        
        
        
This problem is requiring the empirical formula for CaCO₃, which is its molecular formula, and turns out to be equal, this is A. CaCO3 according to the following:
<h3>Empirical formulas:</h3><h3 />
In chemistry, molecular formulas show both the actual type and number of atoms in a chemical compound, based on the elements across the periodic table and the subscripts standing for the number of atoms in the compound. 
However, the empirical formula is a reduced expression of the molecular one, which shows the minimum number of atoms in a compound after simplifying to the smallest whole numbers.
In such a way, since the given compound is CaCO₃ and both Ca and C have a one as their subscript, it is not possible to simplify any further and therefore the empirical formula equals the molecular one this time, making the answer to be A. CaCO3.
Learn more about empirical formulas: brainly.com/question/1247523