17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
Let's understand the situation
You are using an oil based paint .We know oil contains hydrocarbons means CH- bonded compound . Hydrocarbons are known as organic compounds and non polar .The thing non polar doesn't matter much but thing organic matters .
Now coming to water ,water contains OH bonding ,a lone pair is present over O which makes water polar . Although water is also known as inorganic compound.
We know that like dissolves like .In that manner Organic compounds are soluble in only organic compounds and not in inorganic compounds like water .Thus oil paint is insoluble in water as particles don't dissolve
Hence to clean the oil you need organic solvents like toulenw,spirit ,Benzyl compounds etc .
Answer:
330,000
Explanation:
Since there are only 2 significant figures in 0.024 ( and 0.024 is the number with the least number of significant numbers), the answer is 330,000, not 331,000.
Answer:
Option (D)
Explanation:
The super-heating is usually defined as a phenomenon where a certain amount of energy is needed to raise the temperature of the water vapor beyond its normal saturation point. This is also known as the boiling delay.
The super-heat can be mathematically written as:
Super-heat = Current temperature - Boiling point of the liquid.
Thus, super-heat refers to the amount of energy that is required to increase the temperature of vapor beyond its point of saturation.
This super-heat is essential as it helps in preventing the damages of machines like air conditioner, fridge and also helps in their soft running.
Hence, the correct answer is option (D).
Answer:
to identify the element by using flame tests
