Which of these is true of a chemical reaction

a. Energy is either released or absorbed.

b. Energy is always absorbed.

c. Energy is always released.

d. Energy is not transferred.

2. Make a prediction: how can we change (increase/decrease) the furbil population to cause the stingwing population to increase?

Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. What will happen to this enzyme as it follows the food into the stomach where the ph drops to 2.5?

Which of the following equations represents a double-displacement reaction? A. FeS (s) + 2HCl (aq) ® H2S (g) + FeCl2 (aq) B. 2Sb (s) + 3I2 (g) ® 2SbI3 (s) C. Zn (s) + H2SO4 (aq) ® ZnSO4 (aq) + H2 (g) D. 2HgO (s) ® 2Hg (l) + O2 (g)

What is the physical difference between copper and zinc?

Given the following unbalanced thermochemical equation, how much heat will be released from the combustion of 45.5 grams of CH4 in an excess of oxygen gas? CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) + 890 kJ

Which answer best describes an alloy

Olive oil has a density of 0.92 g/mL. How much would 1 liter of olive oil weigh in grams?

How many grams of CO are needed to react with an excess of Fe2O3 to produce (210.3 g Fe) 209.7 g Fe? Show your work. CO (g) + Fe2O3 (s) - - > Fe (s) + CO2 (g)

Which is the molar mass of H2O? 10.02 g/mol 16.00 g/mol 17.01 g/mol 18.02 g/mol

When 4.70 g of a nonelectrolyte solute is dissolved in water to make 935 mL of solution at 28 °C, the solution exerts an osmotic pressure of 943 torr.