Calculate the mass of 0.257 moles of calcium nitrate, Ca(NO3)2. * A.)6.39x10^2 grams
B.)42.2 grams
C.)42.1737
D.)2.57x10^-1grams
E.)1.57x10^-3grams

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

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

The following questions a24 - a26 relate to 100 ml of 0.0150 m solution of benzoic acid (c6h3cooh). ka(c6h3cooh) = 6.4 x 10^-5. what is the ph of the solution after the addition of 1 x 10^-3 moles of naoh? you may assume no volume change to the solution upon addition of the naoh.