Answer:
The freezing point will be 
Explanation:
The depression in freezing point is a colligative property.
It is related to molality as:
Where
Kf= 
the molality is calculated as:
Depression in freezing point = 
The new freezing point = 
Answer:
The Moon weighs about 7.349*10^22 kg
How much does “an elephant” weigh? Grown-up elephants vary between 1.7 tons (small wood elephant cow) and 6 tons (big African elephant bull). Let us pick 2.720 tons or 2720 kg as an average weigh one, this is valid for Asian elephants.
A mole of elephants weighs 6.022 * 10^23 x 2720 kg = 1.638 * 10^27 kg.
That is 1,638 * 10^27 / 7,349*10^22 = 22289 times more.
Answer:
-10778.95 J heat must be removed in order to form the ice at 15 °C.
Explanation:
Given data:
mass of steam = 25 g
Initial temperature = 118 °C
Final temperature = 15 °C
Heat released = ?
Solution:
Formula:
q = m . c . ΔT
we know that specific heat of water is 4.186 J/g.°C
ΔT = final temperature - initial temperature
ΔT = 15 °C - 118 °C
ΔT = -103 °C
now we will put the values in formula
q = m . c . ΔT
q = 25 g × 4.186 J/g.°C × -103 °C
q = -10778.95 J
so, -10778.95 J heat must be removed in order to form the ice at 15 °C.
The percet of Al will be 100 times the mass of Al in the formula divided by the molar mass of the compound.
This table shows all the calculations involved
Compound: Al2 (OH)5 Cl
element # of atomic mass in the %
atoms mass formula
g/mol
Al 2 27 2*27 = 54 g (54 / 174.5)*100 = 30.9%
O 5 16 5*16 = 80 g
H 5 1 5*1 = 5 g
Cl 1 35.5 1*35.5 = 35.5 g
----------------------
molar mass 174.5 g
Answer: 30.9%
