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3 years ago

State the number of sig figs in each value:

Chemistry

1 answer:

Rasek [7]3 years ago

8 0

Answer:

Explanation:

Significant figure implies number of digits that are to be considered. Some rules are required to be considered when writing a given expression to an expected significant figures.

So that:

1) 0.00004050 is 4 significant figures

2) 54.7000 is 6 significant figures

3) 1,000.09 is 6 significant figures

4) 0.039 is 2 significant figures

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Ou have a 5 ml sample of a protein in 0.5 m nacl. you place the protein/salt sample inside dialysis tubing (see fig. 2-14) and p

Oduvanchick [21]

Answer:

Procedure (2)

Explanation:

Assume the dialyses come to equilibrium in the allotted times.

Procedure (1)

If you are dialyzing 5 mL of sample against 4 L of water, the concentration of NaCl will be decreased by a factor of

$\dfrac{5}{4000} = \dfrac{1}{800}$

Procedure (2)

For the first dialysis, the factor is

$\dfrac{5}{1000} = \dfrac{1}{200}$

After a second dialysis, the original concentration of NaCl will be reduced by a factor of

$\dfrac{1}{200} \times \dfrac{1}{200} = \dfrac{1}{40000}$

Procedure (2) is more efficient by a factor of

$\dfrac{40000}{800} = \mathbf{50}$

4 0

3 years ago

If you want to use a serial dilution to make a 1/50 dilution. The first dilution you make is a 1/5 dilution with a total volume

fomenos

Answer:

Explanation:

A serial dilution is a dilution that is made fractionated. The stock solution is diluted, then this now solution is diluted, and then successively. The final dilution is the multiplication of the steps dilutions.

The representation of the dilution is v/v (volume per volume) indicates how much of the stock solution is in the total volume of the solution. So 1/5 indicates 1 mL to 5 mL of the solution. If the final volume must be 1 mL, then the stock solution must be 0.2 mL (0.2/1 = 1/5), and the volume of the solvent is 1 mL - 0.2 = 0.8 mL.

The second solution is done with a dilution of 1/10 or 1 mL of the first solution in 10 mL of the total solution. Because the solution has 1 mL, then the volume of the first solution must be 0.1 mL (0.1/1 = 1/10), and the volume of the solvent that must be added is 1 mL - 0.1 mL = 0.9 mL.

5 0

3 years ago

Write the congruence condition in symbolic form for each pair of triangles in pic above. If wrong answer I will report. If corre

arsen [322]

Answer: ABC&AMN are congruent by ASA comgruence

angle A=A

sideAN=AB

angle M=C

Explanation:

4 0

2 years ago

How does Rb bond with other elements?

Y_Kistochka [10]

Answer: Rb gains two electrons

Explanation:

3 0

3 years ago

#15 fill in the following table regarding ions

Natasha_Volkova [10]

Answer:

$P^{3-}$ Anion Gained 3 18

$Sr^{2+}$ Cation Lost 2 36

$Fe^{3+}$ Cation Lost 3 23

Explanation:

Looking at the ionic notation, the negative symbol (-) indicates that there are more electrons than protons and the positive symbol (+) indicates that there are more protons than electrons.

The number tells you how many was gained or lost.

To determine how many electrons are left, you base this off how many protons there are. The number of protons in an atom is expressed by the atomic number. In a stable atom, you have an equal number of protons and electrons.

Ions occur when electrons are gained or lost.

A cation is positively charged because it LOST an electron. Since there are more protons than electrons, the charge would be positive.

An anion is negatively charged because it gained an electron. Since there are more electrons than protons, the charge would be negative.

Using the explanation above, you can see how the answers were obtained. As for the last column, just use basic math to do this.

The atomic number of Phosphorus (P) is 15, so this means that there are 15 protons. Since it gained 3 electrons, just add 3 to 15:

15 + 3 = 18

Sr has an atomic number 38. Since it lost 2 electrons, just subtract 2 from the atomic number.

38-2 = 36

Fe has an atomic number 26. It lost 3 electrons, so we subtract again.

26-3 = 23

7 0

2 years ago