<span>
Correct Answer:
Option 3 i.e. 30 g of KI dissolved in 100 g of water.
Reason:
Depression in freezing point is a
colligative property and it is directly proportional to molality of solution.
Molality of solution is mathematically expressed as,
Molality = </span>
<span>
In case of
option 1 and 2, molality of solution is
0.602 m. For
option 3, molality of solution is
1.807 m, while in case of
option 4, molality of solution is
1.205 m.
<u><em>Thus, second solution (option 2) has highest concentration (in terms of molality). Hence, it will have lowest freezing point</em></u></span>
Answer:
Mass = 141.6 g
Explanation:
Given data:
Mass of Kr in gram = ?
Volume in L = 9.59 L
Temperature = 46.0°C
Pressure = 4.62 atm
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
46.0+273 = 319 K
4.62 atm × 9.59 L = n× 0.0821 atm.L/ mol.K ×319 K
44.3 atm.L = n×26.19 atm.L/ mol
n = 44.3 atm.L / 26.19 atm.L/ mol
n = 1.69 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 1.69 mol × 83.79 g/mol
Mass = 141.6 g
Answer:
You manage to find a bottle of bromothymol blue and a few extra beakers. You take one of the empty beakers and add some of the first unlabeled solution and some indicator.
The color changes to yellow.
You then add some solution from the other unlabeled flask into this beaker and see the color change to blue.
What are the identities of each unlabeled solution?
Explanation:
Bromothymol blue is a dye and it is used as an indicator.
It is used as a pH indicator.
In acids, it becomes yellow n in color.
In bases, it turns blue.
You take one of the empty beakers and add some of the first unlabeled solution and some indicator. The color changes to yellow.
That means the unlabeled solution is an acid.
You then add some solution from the other unlabeled flask into this beaker and see the color change to blue.
It is a basic solution.
Answer:
a) 157.5 grams of aluminum.
b) 1 mol
c) 9 g
Explanation:
The reaction is :
As per balanced equation
a) 3 moles of hydrogen will be produced from two moles of aluminium.
The atomic mass of aluminium = 27
therefore
3X2 grams of hydrogen is produced from 2 X 27 grams of Al
1 gram of hydrogen will be produced from 
g
therefore 17.5 will be produced from = 9X 17.5 = 157.5 grams of aluminum.
b) as per balanced equation three moles or six gram of hydrogen is produced from 6 moles of NaOH.
Therefore 1 g of hydrogen will be produced from =
or 1 gram will be prepared from = 1 mole
c) from balanced equation three moles are produced from two moles of Al (27X2 = 54 g).
thus from 54 grams gives 6 grams of hydrogen
1 grams will give = 
