Answer:
492.6g
Explanation:
Given parameters:
Number of moles of MgSO₄.7H₂O = 2moles
Unknown:
Mass = ?
Solution:
To find the mass of this compound;
Mass = number of moles x molar mass
Molar mass of MgSO₄.7H₂O = 24.3 + 32 + 4(16) + 7[2(1) + 16]
= 246.3g/mol
Mass = 2 x 246.3 = 492.6g
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, 
12. When the sun is farthest north or south of the equator, the even is called solstice. When it is farthest to the north, it is called summer solstice and when it farthest to the south it is called winter solstice .
13. When neither hemisphere is tilted toward nor away form the sun, it is called equinox. At this time, daylight and night time is as long as each other, or they are both 12 hours long in both hemisphere.
According to VSEPR theory, the structure of the ammonia molecule, NH3, is linear.
So your answer is B) linear