What are 5 ways to tell if it's a chemical change

4 HF (g) + SiO 2 (s) → SiF 4 (g) + 2 H2 O (l) What mass of water (in grams) is produced by the reaction of 67.0 g of SiO2?

Consider this reaction: HCO3 - + H2S → H2CO3 + HS - Which is the conjugate acid? H2S HCO3 - HS - H2CO3

Which of the following is true of organic compounds? They always contain hydrogen. Each has distinctive chemical and physical properties. They are only found in living things. They cannot be synthesized.

Which project was designed to visit the moon? A. Gemini B. Mercury C. Apollo D. Skylab

What would happen if you put two cups of water and add 1 tablespoon of sugar and a table spoon of black pepper?

A 150ml sample of hydrochloric acid completely reacted with 60.0mL of a 0.100 M NaOH solution. What was the original concentration of the HCl solution

Rearrange in to a quadratic 5.333 = (0.6 + 2p) ² / (0.135 - p)

How hot would a 2.3 L balloon have to get to expand to a volume of 3.0 L? Assume the initial temperature of the balloon is 24 °C, and that the pressure inside the balloon remains constant. A. 3 K B. 42 K C. 128 K D. 390 K

Which pair of nitrogen bases will form a bond in a DNA molecule? a. cytosine and adenine b. adenine and thymine c. guanine and thymine d. thymine and cytosine

Most meteors that fall into the earths atmosphere burn up before reaching the ground. Why is this?