Answer:
Formula of EPSOM salt = MgSO4.7H2O
molecular mass of MgSO4.7H2O = atomic mass of Mg + atomic mass of S + 4 × atomic mass of O + 7 { 2 × atomic mass of H + atomic mass of O }
= 24 + 32 + 4× 16 + 7{ 2 × 1 + 16 } g/mol
= (24 + 32 + 64+ 126 ) g/mol
= 246 g/mol
molecular mass of total water = 7 × ( 2× atomic mass of H + atomic mass of O )
= 7 × 18 = 126 g/mol
now ,
% mass of H2O in EPSOM salt = {total molar mass of H2O/molar mass of Epsom salts }× 100
= {126/246 } × 100
= 12600/246
= 51.21 %
Explanation:
i have done it hope it helps
Answer:
25.907°C
Explanation:
In Exercise 102, heat capacity of bomb calorimeter is 6.660 kJ/°C
The heat of combustion of benzoic acid is equivalent to the total heat energy released to the bomb calorimeter and water in the calorimeter.
Thus:
= heat of combustion of benzoic acid
= heat energy released to water
= heat energy released to the calorimeter
Therefore,
![-m_{combust}*H_{combust} = [m_{water}*c_{water} + C_{calori}]*(T_{f} - T_{i})](https://tex.z-dn.net/?f=-m_%7Bcombust%7D%2AH_%7Bcombust%7D%20%3D%20%5Bm_%7Bwater%7D%2Ac_%7Bwater%7D%20%2B%20C_%7Bcalori%7D%5D%2A%28T_%7Bf%7D%20-%20T_%7Bi%7D%29)
1.056*26.42 = [0.987*4.18 + 6.66](
- 23.32)
27.8995 = [4.12566+6.660]( - 23.32)
( - 23.32) = 27.8995/10.7857 = 2.587
= 23.32 + 2.587 = 25.907°C
B) differences in temperature
Explanation:
The factor that most directly affects the flow of ocean currents is the differences in ocean temperature from one place to another.
Ocean current is the directional movement of the ocean water in its basin.
The main cause of ocean current is differences in temperature.
- Ocean water on the surface receives direct sunlight.
- This warms and the surface and decreases their density.
- When winds blows over them, they cool and sink under their own weight.
- The less cold water in depths rise to replace them.
- This exchange of ocean water due to loss and gain of heat cause ocean current.
learn more:
Ocean density brainly.com/question/6760255
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To give 33.6 dm³ hydrogen gas at STP, 18.06 x 10²³ atoms of Na must react completely.
<h3>What is Mole concept ?</h3>
A mole is a unit of measurement used to measure the amount of any fundamental entity (atoms, molecules, ions) present in the substance.
As according to the given equation, 2 moles (ie 12.04 x 10²³ atoms) of Na-atoms produces 1 mole (22.4 ltr) of H₂-gas.
Hence, to produce 33.6 ltr (equivalent to 33.6 dm³) of H₂-gas produced by ;
= 12.04 x 10²³ atoms of Na / 22.4 ltr of H₂-gas x 33.6 ltr
= 18.06 x 10²³ atoms of Na
Hence, To give 33.6 dm³ hydrogen gas at STP, 18.06 x 10²³ atoms of Na must react completely.
Learn more about Mole concept here ;
brainly.com/question/20483253
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Answer:
B. People live longer than they used to
Explanation:
None of the other answers are correct.
