Use the information to answer the following question. Students are trying to calculate the heat of reaction for the following target reaction.
A + 3B → 3C + 2D
They find the heat of reactions for the two reactions as shown.
A + 2B → C + D ΔH= -20 kJ

B → 2C + D ΔH= -45 kJ

When the students used Hess’s Law correctly, what is the heat of reaction for the target reaction?

A.
+65 kJ

B.
+25 kJ

C.
-65 kJ

D.
-25 kJ

1. list three scientific reasons cockroaches may fly.

Which statements are true concerning mineral formation? check all that apply. the slower the cooling, the larger the crystals. the faster the cooling, the smaller the crystals. crystals formed from magma are smaller than crystals formed from lava. minerals can only form in solutions when the solution is heated deep underground. when a solution cools, elements and compounds leave the solution and crystallize as minerals. minerals formed from hot water solutions can form narrow channels in the surrounding rock.

How many moles of oxygen react with 12 moles of aluminum