The solution contains 39.4% of LiF. Assume that the solution is 100ml. The molar mass of LiF is 25.939, the amount of LiF in mole would be: 100ml * 1g/ml * 39.4%/ 25.939g/mol= 1.52 mol LiF
Then the mass of the water would be: 100gram- 39.4g= 60.6g
If the molar mass of water is 18.015 the mole of the water would be: 60.6g/ 18.015g/mol= 3.36 mol
.
The mole fraction would be:1.52 mol/ 1.52+3.36= 0.339
Answer:
Option (A)
Explanation:
The temperate forest usually covers the tropical and the taiga region. The trees in this forest region experience all the four seasons namely summer, autumn, winter and spring. It comprises approximately 25% of the total forest-covered region on earth. The leaves of these trees change color during the autumn season, which eventually falls off during the winter season, and again, new leaves grow back during the spring season. This enables the plants to survive and go through the cold temperature in the winter.
Thus, the correct answer is option (A).
Answer:
3120.75J
Explanation:
So, we have the formula 
. For this example, q is the heat energy in Joules, m is the mass in grams, c is the specific heat capacity in 
, and 
t is the change in temperature. In this case, m = 47.5g, c = 0.9 , and t = 94-21 = 73°C. Plugging in the values, we get the joules of heat required to raise 47.5g of Al from 21°C to 94°C which is stated above. You can double check my answer but that should be it. An important thing to be aware of are the units. Sometimes, the heat capacity may not be . I may be in Kelvin or something. Anyways, hope this helps.
Answer:
The answer to your question is 58.7 g of Ca(OH)₂
Explanation:
Data
mass of Ca(OH)₂ = ?
mass of HNO₃ = 100 g
Process
1.- Write the balanced chemical reaction
Ca(OH)₂ + 2HNO₃ ⇒ Ca(NO₃)₂ + 2H₂O
2.- Calculate the molar mass of the reactants
Ca(OH)₂ = 40 + 32 + 2 = 74 g
HNO₃ = 1 + 14 + 48 = 63 g
3.- Use proportions to calculate the mass of Ca(OH)₂
74 g of Ca(OH)₂ ----------------- 2(63) g of HNO₃
x ----------------- 100 g of HNO₃
x = (100 x 74) / 2(63)
x = 7400 / 126
x = 58.7 g
