Answer:
B.) 36.0 grams
Explanation:
To find the mass of water, you need to (1) convert grams H₂ to moles (using the molar mass), then (2) convert moles H₂ to moles H₂O (using mole-to-mole ratio from reaction coefficients), and then (3) convert moles H₂O to grams (using the molar mass). It is important to arrange the conversions in a way that allows for the cancellation of units.
Molar Mass (H₂): 2(1.008 g/mol)
Molar Mass (H₂): 2.016 g/mol
Molar Mass (H₂O): 2(1.008 g/mol) + 15.998 g/mol
Molar Mass (H₂O): 18.014 g/mol
2 H₂ + O₂ -----> 2 H₂O
^ ^
4.0 g H₂ 1 mole 2 moles H₂O 18.014 g
--------------- x ---------------- x ------------------------ x --------------- = 36 g H₂O
2.016 g 2 moles H₂ 1 mole
The earths crust and the skin of rock on the outer layer of earth.
Well, you don't need enzymes (biological catalysts) if you're willing to wait a century or two to digest a burger.
Without catalysts, complex reactions like digestion would take too long and the organism could not extract energy from the nutrients it eats in a practical time frame.
In addition, speed is everything in the biological world.
Some reactions and their speed relative to other organisms reactions determines who survives and who doesn't, among other aspects of life.
If a plant is slow to photosynthesize and grow in a habitat high in competition for sunlight real estate, other autotrophs will surely take over.
It should be option (A) because conduction is the transfer of heat energy from one place to another by vibrations/motion of the molecules. I hoped I helped.