How many isotopes does carbon and oxygen have?

How many grams of naoh are needed to make 0.250 liter of a 0.500 m solution of naoh? 0.125 g 5.00 g 2.00 g

Agas can holds 2.0 gal of gasoline. what is this quantity in cubic centimeters?

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90