If a chemical change requires energy, which of the following could be the source of the energy? select one: a. settling the mixture for 20 minutes b. adding more substance to the observed material c. measuring mass from a beam balance d. heating with a flame

What is the maximum amount of al2(so4)3 which could be formed from 15.84 g of al and 12.89 g of cuso4?

If 3.00 g of titanium metal is reacted with 6.00 g of chlorine gas, cl2, to form 7.7 g of titanium (iv) chloride in a combination reaction, what is the percent yield of the product?

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.