What are signs that a chemical reaction has occured

Calculate the theoretical oxygen demand (mg/L). of a solution containing 450mg of glucose (C6H12O6). in 2 L of distilled water.

Which of the following is a homogeneous mixture? a. iced tea b. apple pie c. orange juice d. vegetable soup User: A group of students want to identify a sample of matter. They observed the sample and made the observations below.

Where are the most reactive metals located? A) Upper left of the periodic table B) Lower left of the periodic table C) Upper right of the periodic table D) Lower right of the periodic table

The mass of a rock is 2.491g. its volume is 1.71 ml. what is the density

What is the mass, in grams, of a sample of 7.83 * 1024 atoms of helium (He) ? Show your work or explain the steps that you used to determine your answer.

How can a chemical reaction be sped up? Pack in more of the reactant to increase the_.

How does a mixture of benzoic acid and benzaldehyde can be isolated separately by extractions?

What is a compound? a) a combination of two or more substances that are not chemically combined b) a combination of two or more elements that are combined in a certain ratio

A gas has a volume of 75mL at a pressure of 200.0 kPa. What will be the new volume be in mL if the pressure is decreased to 60.0 kPa in sig figs

Give two reasons why it's important to work with a partner in a lab