Which of the following always occurs in a chemical reaction?

A) a gas is given off.
B) a solid is produced,
C) a new substance is produced.
D) a colour change takes place.

The overall chemical reaction for photosynthesis isshown below: 6co2 + 6h20 → c6h12o6 + 602what mass of glucose (c6h1206) can form from71.89 g co2? (molar mass of c6h1206 = 180.18g/mol; molar mass of co2 = 44.01 g/mol)71.89 g co2=g c6h1206

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.

What is the chemical name of the compound na2co3? use the list of polyatomic ions and the periodic table to you answer. a. sodium carbon oxide b. sodium carbonate c. sodium(ll) carbonate d. sodium oxalate