How do you know a chemical reaction has taken place?

Electronegativity values decrease as you move across a period from left to right. True False

Butane gas is used as the fuel in disposable lighters. It burn in oxygen to form carbon dioxide gas and water vapor. What mass of carbon dioxide is produced when 53.3 g of butane is burned in 103.9 g of oxygen

Sulfuric acid (H2SO4) has a molar mass of 98.1 g/mol. How many oxygen atoms are found in 75.0 g of H2SO4? A. 1.15 * 10^23 B. 1.84 * 10^24 C. 4.61 * 10^23 D. 7.87 * 10^23

13. A new mystery novel will cost Ally $26.60. If she earns $6.65 an hour, how many hours will she have to work in order to purchase it? a. 2 b. 19.95 C. 4 d. 189

A student has a 2.123 g sample of a hydrated salt. she heats it to drive off all the water. after heating to constant mass, the salt weighs 1.861 g. the anhydrous salt is copper (ii) phosphate. what is the empirical formula of the hydrated salt?

What is the total pressure when 0.400 g of H2, 2.00 g of N2, and 10.5 g of CO2 are injected into a 10.0 liter flask at 273 K?

The balanced chemical equation for the combustion of methane is: CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g) Which of the following statements concerning this chemical equation is/are correct? 1.

In one kind of nuclear reaction, two nuclei fuse, or join together, to form a larger nucleus. This kind of reaction happens only at very high pressures. Explain why such high pressures are necessary to cause these reactions to occur.

Check the approach to obtain the correct conversion equation. Use the temperature in °F to find the temperature in °C. °C

What is the volume of a gas at 50.0 Celsius and. 80 atm if there are. 75 moles of a gas present?