Which of the following is a balanced chemical equation?

2 Mg + HC1 → MgCl2 + H2

SO2 + O2 + 2 H2O → 4 H2SO4

2 Fe2O3 + 3 C → 4 Fe + 3 CO2

H2O2 → H2O + O2

How does the amount of freshwater on Earth compare to the amount of saltwater on Earth?

Hich is an example of a chemical change? mixing of poster colors formation of clouds metal corroding in salt water sugar dissolving in water separating salt from seawater

As the temperature of a sample of gas falls from 37.8 ºC to 77.9 ºC, its pressure falls to 103.8 mm Hg. If the volume did not change, what was the original gas pressure? Select one: a. 91.9 b. 50.4 c. 120 d. 414

A 1.0-l buffer solution initially contains 0.30 mol of nh3 and 0.30 mol of nh4cl what mass of the correct reagent should you add?

Which structures are found on sponges? pores medusae polyps stinging cells

What is a neutral atoms oxidation number

Suppose 30 grams of NaCl are placed in 900 mL of water. What is the molarity of this solution?

After a particularly cold day outside you go home to make some tea. you heat the water in the mug so that botch are about 75 degrees celcious. the tea bag is only 30 degrees celcious and the room is around 26 degrees celcious.

For main-group elements using the older numbering system the group number on the periodic table corresponds to which characteristic of the elements of that group

In the vertical columns of the periodic table, as the atomic numbers increase: a. the number of electron shells increases. b. the ionization energies increase. c. the number of electrons in the valence shell increases. d.