Answer : The mass of the water in two significant figures is, 
Explanation :
In this case the heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of iron metal = 
= specific heat of water = 
= mass of iron metal = 32.3 g
= mass of water = ?
= final temperature of mixture = 
= initial temperature of iron metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get
Therefore, the mass of the water in two significant figures is,
B. It has a negative charge and much less mass than a proton.
Answer:
Mass = 9.58 g
Explanation:
Given data:
Mass of Zn = 2g
Theoretical yield of ZnI₂ = ?
Solution:
Chemical equation:
Zn + I₂ → ZnI₂
Number of moles of Zn:
Number of moles = mass/molar mass
Number of moles = 2g / 65.38 g/mol
Number of moles = 0.03 mol
Now we will compare the moles of Zn and ZnI₂.
Zn : ZnI₂
1 : 1
0.03 : 0.03
Mass of ZnI₂:
Mass = number of moles × molar mass
Mass = 0.03 mol × 319.22 g/mol
Mass = 9.58 g
