Hydrogen peroxide was catalytically decomposed and 75.3 mL of oxygen gas was collected over water at 25°C and 742 torr. What mass of oxygen was collec

0.0928 grams of oxygen was collected.

Explanation:

Volume of oxygen gas collected = V= 75.3 mL = 0.0753 L (1 mL = 0.001 L)

Temperature of the gas = T = 25°C = 25+ 273 k = 298 K

Pressure of the gas = P - = 742 Torr - 24 Torr = 718 Torr

1 atm = 760 Torr

Moles of oxygen gas = n

Using an ideal gas equation;

n = 0.0029 mol

Mass of 0.0029 moles of oxygen gas :

0.0029 mol × 32 g/mol = 0.0928 g

0.0928 grams of oxygen was collected.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6