A sample of hydrated copper sulfate weighs 25g. After heating to remove the water of crystallization, the anhydrous copper sulfate weighs 16g. What is the percentage of water of crystallization in the original sample?

A sample of hydrated copper sulfate ($CuSO_4 \cdot xH_2O$) weighs 25 g. Upon heating to drive off all the water, the anhydrous copper sulfate ($CuSO_4$) remaining weighs 16 g. What is the value of 'x' (the number of water molecules of crystallization)?

Which law implies that the mass ratio of elements in a compound is always a whole number ratio?

Hydrogen and oxygen combine to form water (H2O). If 4g of hydrogen reacts completely with oxygen to form water, what mass of oxygen is required?

10g of hydrogen reacts with 80g of oxygen to form water. Which law of chemical combination does this demonstrate?

10 g of a metal oxide on strong heating gave 6.4 g of metal. If the formula of the metal oxide is $M_2O_3$, what is the atomic mass of the metal M?

Which law states that a chemical compound always contains the same elements combined together in the same fixed proportion by mass?

Which law explains the observation that 1g of hydrogen always combines with 8g of oxygen to form 9g of water?

Two different samples of copper(II) oxide were analyzed and found to contain the same percentage of copper by mass. Which law does this illustrate?