Help please i’m being timed!

What is the molar mass of a gas that has density of 2.054 g/l

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.