Before free oxygen gas became abundant in the oceans and atmosphere, it reacted with a metal and produced what type of formations?

a. the ionosphere

b. the ozone layer

c. banded iron formations

d. stromatolites

Dissolving 3.05 g of an impure sample of CaCO₃ in an excess of HCl acid produced 0.636 L of CO₂ (measured at 25°C and 792 mmHg). Calculate the percent by mass of CaCO₃ in the sample. State any assumptions.

4-dimethylaminopyridine (DMAP; below) is an extremely useful molecule in organic chemistry. One professor here at OSU often comments to graduate students when theirreaction isn't working just to sprinkle a little DMAP into their reaction.

If 20.0 g of copper (ii) chloride react with 20.0 g of sodium nitrate, what mass of sodium chloride is formed

Will give brainliest Explain why someone would choose to use octane in a car engine rather than octene?

Why does a catalyst not need to be replaced for a long time?

Compared to the radius of a chlorine atom, the radius of a chloride ion is (1) larger because chlorine loses an electron (2) larger because chlorine gains an electron (3) smaller because chlorine loses an electron (4) smaller because chlorine gains

What do you think made the blizzard so dangerous?

If 6 moles of a compound produce 84 J of energy, what is the a Hreaction in J/mol?

If you were traveling through space and landed on a different planet, how might your mass and weight compare to their values on Earth? Why?

Which principle explains why it is necessary to have safety belts in cars?