Answer:
Phenolphthalein is an acid indicator, which means when we add water (pH 7) to it, it ionizes giving a pink color. We all know acid gives in solution. When we add phenolphthalein to acid due to the common ion effect concentration increases. turned the solution pink.
Explanation:
Answer:
That would be helium, with a melting point of 0.95 K (-272.20 °C)—although this happens only under considerable pressure (~25 atmospheres). At ordinary pressure, helium would remain liquid even if it could be chilled to absolute zero.
Answer:
D. Its temperature will remain 100 C until all the vapours condenses
Explanation:
Heat absorbed by a substance to change the state of matter is known as latent heat. This heat is utilized to break the bonds between atoms of the substance so that they can undergo phase change.
So, when water boils at 100 degree Celsius then temperature will remain constant unless and until all the water changes into vapor. As it is the latent heat that breaks the bonds between hydrogen and oxygen atoms of water so that liquid state can change into gaseous state.
Since latent heat is a hidden heat, that is why, it does not get reflected and there is no change in temperature due to it.
Thus, we can conclude that it is true that temperature will remain at 100°C until all the vapor condenses for a sample of water vapor at 101°C as it cools.
Answer: Option (a) is the correct answer.
Explanation:
Since it is given that the mass of a jelly bean is less than the mass of a gum drop.
So, when we counted out 10 of each kind of candy and measured the mass of each kind of candy, the mass of the jellybeans would be less than the mass of the gumdrops.
This is because mass of jelly bean is less and even if we take take or more jelly beans then also their total mass will remain less than the total mass of same number of gum drops.
<u>Answer:</u> The percent composition of hydrogen in the sample is 15.22 %
<u>Explanation:</u>
We are given:
Mass of hydrogen = 7 grams
Mass of nitrogen = 32 grams
Mass of carbon = 7 grams
Total mass of the sample = 7 + 32 + 7 = 46 grams
To calculate the percentage composition of hydrogen in sample, we use the equation:
Mass of sample = 46 g
Mass of hydrogen = 7 g
Putting values in above equation, we get:
Hence, the percent composition of hydrogen in the sample is 15.22 %
