When the concentration of a is doubled, the rate for the reaction: 2a+b → 2cquadruples..?

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

3) in peaches, [oh]=3.16x10-11 m a) find [h+ ] b) what is the ph? c) is the solution acidic, basic, or neutral?