Which equation represents an oxidation-reduction reaction? A: CH4 + 2O2 --> CO2 + 2H2O
B: H2SO4 + Ca(OH)2 --> CaSO4 + 2H2O
C: MgCrO4 + BaCl2 --> MgCl2 + BaCrO4
D: Zn(NO3)2 + Na2CO3 --> 2NaNO3 + ZnCO3

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

Asa choose the correct set of reaction coefficients to properly balance the following chemical equation according to the law of conservation of mass: __s8 + __o2 ==> __so2 1, 1, 8 1, 8, 1 1, 8, 8 8, 1, 1

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.