The structure of hydrogen sulphide (Mr = 34.1 g mol-1) is analogous to water (Mr = 18.0 g mol-1). Despite having larger molecular mass than water, the boiling point of hydrogen sulphide at STP is -60.2°C whereas the boiling point of water is 99.61 °C under the same condition. Explain this observation.

Phosphoric acid is a triprotic acid ( =6.9×10−3 , =6.2×10−8 , and =4.8×10−13 ). to find the ph of a buffer composed of h2po−4(aq) and hpo2−4(aq) , which p value should be used in the henderson–hasselbalch equation? p k a1 = 2.16 p k a2 = 7.21 p k a3 = 12.32 calculate the ph of a buffer solution obtained by dissolving 18.0 18.0 g of kh2po4(s) kh 2 po 4 ( s ) and 33.0 33.0 g of na2hpo4(s) na 2 hpo 4 ( s ) in water and then diluting to 1.00 l.

What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm?

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?