It is logical to assume that they hydrogen ion concentration in an aqueous solution of a strong monoproctic acid equals the molarity of the acid because ions which are charged,for example ammonium ion (NH4+), which can be derived by the addition of a proton to a molecular base.
A catalyst is a substance that increases the rate of a chemical reaction without itself being consumed . (ans: second choice)
Assume there is 100g of the substance at first
Day and night is due to the earth rotating. Seasons are due to the earth rotating on a slightly tilted axis, causing light to be shone on different parts of the earth more directly during different parts of the year. Constellations changing throughout the night are because of the earth moving and rotating. Throughout the year, the earth moves, causing us to be facing different directions in different parts of the year. The North Star does't move because it is close to Earth's line of axis, and therefore does not appear to move.