Answer:
2.8 m
Explanation:
From the question given above, the following data were obtained:
Number of mole KBr = 0.210 mole
Mass of water = 0.075 kg
Molality of KBr =?
Molality is simply defined as the mole of solute per unit kg of water. Mathematically, it can be expressed as follow:
Molality = mole of solute / Kg of water.
With the above formula, we can obtain the molality of the KBr solution. This can be obtained as follow:
Number of mole KBr = 0.210 mole
Mass of water = 0.075 kg
Molality of KBr =?
Molality = mole of solute / Kg of water.
Molality = 0.210 / 0.075
Molality = 2.8 m
Therefore, the molality of the KBr solution is 2.8 m.
Answer:
Decomposition and Al and P
they might be looking for thermal decompositioin as this one happens at 2000 degrees
Explanation:
The half life of a substance is the time taken by a radioactive substance to decay by half its original mass. In this case, the half life of Potassium-40 is 1.3 billion years.
Original mass of Potassium-40 = 12 g (100%)
New mass after the decay = 3 g ( 25 %, since 75% was replaced by argon)
New mass = Original mass × (1/2)^n ; where n is the number of half lives.
3 = 12 × (1/2)^n
(1/2)^n = 1/4
n = 2
Therefore; the time taken will be 1.3 × 2 = 2.6 Billion years
Answer:
A shell protects the bird
Explanation:
