Hello' please help this is my last hope Please don't still the points I really need help so please don't do that. Any help is appreciated!

How have the greenhouse gasses increased from the year 2000 to 2018

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)

Select the statement that describe chemical properties a. antacid tablets neutralize stomach acid b. helium is the lightest monatomic element c. water freezes at 0 celsius d. mercury is liquid at room temperature