Chemistry, 26.03.2020 03:20 ReeseMoffitt8032

Calculate the change in ph if 0.070 g of solid naoh is added to 100 ml of the solution in the problem above.

Answers: 1

Show answers

Answers

Answer from: Isabellawuzhere

Assuming the pH of a buffer solution that contains 0.65 M NaH2PO4 and 0.11M Na2HPO4 is 6.44.

Calculate the change in pH if 0.070 g of solid NaOH is added to 100 mL of the solution in the problem above

∆ pH = 0.08

Explanation:

Calculate concentration in mmoles of each species before adding the NaOH.

[NaH2PO4] = M NaH2PO4 x mL NaH2PO4 = (0.65)(100) = 65 mmoles NaH2PO4

[Na2HPO4] = M Na2HPO4 x mL Na2HPO4 = (0.11)(100) = 11 mmoles Na2HPO4

When you add the strong base NaOH to the buffer, it will react with the acid part of the buffer (i.e. the species with the most Hs --- NaH2PO4).

0.070 g NaOH x (1000 mg / g) x (1 mmole NaOH / 40.00 mg NaOH) = 1.75 mmoles NaOH

[Concentration] . . . . . .NaH2PO4 + NaOH ➡ Na2HPO4 + H2O

initial . . . . . . . . . . 65 . . . . . .1.75 . . . . . . . . .11

change . . . . . . . .-1.75 . . . . .-1.75 . . . . . . .+1.25

final . . . . . . . . . . .63 . . . . . . . .0 . . . . . . . . . .13

pKa for H2PO4- = 6.2 x 10^-8; pKa = 7.21

pH = pKa + log ( [Na2HPO4] /[NaH2PO4]) = 7.21 + log (13/ 63) = 7.21 - 0.69 = 6.52

∆pH is minute (from 6.44 to 6.52). = 0.08

Answer from: Quest

Mass is the amount of matter in an object. weight is the measurement of the pull of gravity on an object. say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165) now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon. however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant. in conclusion it is possible for your weight to change as your mass remains constant.

Another question on Chemistry

Chemistry, 22.06.2019 20:30

Citric acid has a ph between 1 and 3. it is considered to be aa. weak acidb. weak basec. strong based. strong acid

Answers: 2

Answer

Chemistry, 23.06.2019 09:30

Organisms that live in the alpine and taiga biomes have developed unique adaptations that aid in their survival. moss campion is one of the plants found in the alpine biome. it has small leaves and a cushion shape that protect it from the wind and freezing temperatures in the alpine. how has the moss campion adapted to enable its survival in the alpine biome? a. waxy needles b. cone-shaped c. thin trunks d. low-growing

Answers: 1

Answer

Chemistry, 23.06.2019 13:30

Determine the rate law, including the values of the orders and rate law constant, for the following reaction using the experimental data provided. a + b yields products trial [a] [b] rate 1 0.30 m 0.25 m 1.2 × 10-2 m/min 2 0.30 m 0.50 m 4.8 × 10-2 m/min 3 0.60 m 0.50 m 9.6 × 10-2 m/min

Answers: 1

Answer

Chemistry, 23.06.2019 16:10

Which scientist established the law of octaves?

Answers: 1

Answer

You know the right answer?

Calculate the change in ph if 0.070 g of solid naoh is added to 100 ml of the solution in the proble...

Questions