A sample of sodium peroxide, Na2O2, was reacted with an excess of water.

2 Na2O2 (s) + 2 H2O (l) —> 4 NaOH (aq) + O2 (g)

All of the sodium peroxide reacted, and the oxygen was collected over water at 21 degrees Celsius. The barometric pressure was 771 mm Hg. However, the level of water inside the tube was 25.0 cm above the level of water outside the tube. If the volume of gas in the tube is 31.0 mL, how many grams of sodium peroxide were in the sample?

According to the solutions in the back of my Chemistry book, the answer is 0.194 g Na2O2. I can’t seem to figure out how to get this answer, though. Any help would be very much appreciated!

Asmall amount of a solid is added to water. the observation made after fifteen minutes is shown in the figure. which of these solids has been probably added to water? a) oil b) sand c) sugar d) wood chips

Microtubular fibers that assist in the movement of chromosomes during nuclear division in conjunction with proteins, makes up the small and large organelle pieces that assemble prior to translation three-base nucleotide sequence that can complementarily pair with the functional transcript, allowing a particular material to be brought to a ribosome particular time in the cell cycle when the cell’s systems determine if the cellular conditions are appropriate to continue through the cycle time in the cell’s cycle when proteins are made and organelles are duplicated enzyme that allows proper nucleotide bonding during transcription specific dna sequence which will initiate gene transcription division of the cell’s cytoplasm specific bond that forms between two amino acids when a carboxyl group binds to a amino group three-base sequence that does not code for a particular amino acid a paired organelle which facilitates the formation of movement microtubules time in the cell’s cycle when the microtubular structures exert an equal pressure on the cell’s genetic material

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '