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, 
Answer:
CaO(s) + 2NH4Cl(aq) -------> CaCl2(aq) + H2O(l) + 2NH3(g)
Explanation:
The solvay process is an important process in the chemical industry. In this process, ammonia gas is first dissolved in concentrated brine to form a mixture known as ammoniacal brine. This solution is made to trickle down the tower. A counter stream of carbon dioxide is forced up the tower. The two substances react to form sodium hydrogen trioxocarbonate IV. This substance is only slightly soluble and separates out as a solid sludge. The product is now dried and heated to give sodium trioxocarbonate IV.
The overall reaction of the process can be given as;
CaO(s) + 2NH4Cl(aq) -------> CaCl2(aq) + H2O(l) + 2NH3(g)
Calcium chloride is merely a by-product.
Magnesium has just two valence electrons
La temperatura es un cambio físico