How many grams of gas are present at 221 mL of Ar and 253 torr at -27 degree Celsius

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

‘which reaction would most likely require the use of an inert electrode?

Astudent uses universal ph paper to find the ph of three solutions . solution a has a ph of 5 solution b has a ph of 11 and solution c has a ph of 7 identify which solution is acidic which solution is neutral and which solution is basic