the student calibrates the pipet. The calibrated pipet delivers a mean volume of 24.991 mL with an uncertainty of ±0.004 mL. The student then uses the calibrated 25 mL pipet to deliver a total of 74.973 mL of solution. What is the uncertainty in the delivered 74.973 mL

Can someone me with 3 and 4 plz. this is for masteries test.

Choose an equation that represents an enzyme-catalyzed reaction. (a) enzyme + substrate → enzyme-substrate complex (b) enzyme + substrate ←−→ enzyme + products (c) enzyme + substrate ←−→ enzyme-substrate complex → enzyme + products (d) enzyme + substrate ←−→ enzyme-substrate complex → enzyme-substrate complex + products

In an exothermic reaction at equilibrium, what is the effect of lowering the temperature? a. the reaction makes more products. b. the reaction makes more reactants. c. the reaction is unchanged.