Consider the table below. In a sample of 100 g of sucrose, what would be the expected mass of hydrogen?

Consider the table below. Why are the mass ratios of copper and chlorine not the same for Compound I and Compound II?

When mercury(II) oxide is heated, it decomposes into mercury and oxygen. If a 28.4 g sample of mercury(II) oxide decomposes producing 2.0 g of oxygen, what is the percent by mass of mercury in the sample?
Sort the following words- Which represent physical changes and which represent chemical changes?


Coffee (various dissolved compounds in water)
Brass (a solid mixture of copper and zinc)
Rubbing alcohol (isopropyl alcohol dissolved in water)
Vinegar (acetic acid dissolved in water)
A 2 gram sample of sucrose is 6.50% hydrogen. What is the mass percentage of hydrogen in 300 g of sucrose? Explain your reasoning.
Which two are categorized as pure substances?
What are examples of homogeneous mixtures?
Which among the following are examples of heterogeneous mixtures?
Identify the two compounds from the following substances.