Answer: 4.22 grams of solute is there in 278 ml of 0.038 M 
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
where,
n = moles of solute
= volume of solution in L
Now put all the given values in the formula of molality, we get

mass of
= 
Thus 4.22 grams of solute is there in 278 ml of 0.038 M 
Answer:- It is choice D. 
Explanations:- In general, a neutralization reaction is the reaction of an acid with base to form salt and water.
in first reaction the reaction is taking place between ammonia(a base) and hydrochloric acid(an acid) to form their salt(ammonium chloride). So, it is an acid-base neutralization reaction.
In second reaction, sodium hydroxide(a base) is reacting with acetic acid(an acid) to form their salt(sodium acetate) and water. So, it is an acid-base neutralization reaction.
In third reaction, Nitric acid is reacting with calcium hydroxide(a base) to form a salt(calcium nitrate) and water. So, it is an acid-base neutralization reaction.
In fourth reaction, sulfuruc acid is reacting a sodium chloride(a salt) to give a double replacement reaction. It is not an acid-base neutralization reaction as it's not taking place between an acid and base.
So, the correct choice is D. 
Because potassium is more reactive than hydrogen
Answer:
C
Explanation:
Large chlorine atoms can not fit within the atoms of boron