Answer: Option (d) is the correct answer.
Explanation:
A change that does not cause any difference in chemical composition of a substance are known as physical change.
For example, shape, size, mass, volume, density, etc of a substance are all physical changes.
And, a change that causes changes in chemical composition of a substance is known as chemical change.
For example, precipitation, reactivity, toxicity etc are chemical change.
Therefore, change in temperature, chemical precipitation of a solid
, production of a gas are all indications of a chemical change.
Thus, we can conclude that change in volume would not necessarily indicate a chemical reaction.
To solve multiply the mL by the mg/ml so 375*40=15000mg
Answer:
Pressure and volume have an inverse relationship when temperature is constant. This is Boyle's Law.
Explanation:
P1V1=P2V2
You can infer that the different elements have different light spectrum frequencies, causing the different light colors.
Answer:
i) 16 mL of ethanol
ii) maximum amount recoverable = 15.52 g; percentage recovery = 97%
iii) maximum amount recoverable = 15.1 g
percentage recovery = 94.4%
Explanation:
Solubility = mass/volume
i) mass of ethanol recovered per mL of ethanol when cooled from 78 °C to 0 °C = 0.13 - 0.03 = 0.10 g
Therefore 1.60 g of Y will require a minimum of 1.60 x 1 mL/0.10 g = 16 mL of ethanol
ii) maximum amount of Y that can be recovered is given as :
mass of Y left in solution after recrystallization, x is obtained
0.03 g/mL = x g/16 mL
x = 0.48 g
maximum amount recoverable = 16 - 0.48 = 15.52 g
percentage recovery = (15.52/16) x 100 % = 97%
iii) if 30 mL of ethanol were used:
mass of Y left in solution after recrystallization, x is obtained;
0.03 g/mL = x g/30 mL
x = 0.03 x 30 = 0.9 g
maximum amount recoverable = 16 - 0.9 = 15.1 g
percentage recovery = (15.1/16) x 100% = 94.4%