4. A sample of silicon contains<br> 5.23 x 1011 atoms. Write this amount<br> as a whole number.

Two species, A and B, are separated on a 2.00 m long column which has 5.000 x 103 plates when the flow rate is 15.0 mL/min. A sp

sergiy2304 [10]

Explanation:

The given data is as follows.

$t_{m}$ = 30.0 sec, $t_{r1}$ = 5 min = $5 \times 60 sec$ = 300 sec

$t_{r2}$ = 12.0 min = $12 \times 60 sec$ = 720 sec

Formula for adjusted retention time is as follows.

$t'_{r} = t_{r} - t_{m}$

= 300 sec - 30.0 sec

= 270 sec

$t'_{r2}$ = 720 sec - 30 sec

= 690 sec

Formula for relative retention ( $\alpha$ ) is as follows.

$\alpha = \frac{t'_{r2}}{t'_{r1}}$

= $\frac{690 sec}{270 sec}$

= 2.56

Thus, we can conclude that the relative retention is 2.56.

4 0

2 years ago

Jesse travels 3.0 meters east and then turns and travels 4.0 meters north. The trip requires 35 seconds. What is his velocity? 0

melisa1 [442]

Displacement = √(3² + 4²)
Displacement = 5 meters north east

Velocity = displacement / time
Velocity = 5 / 35
Velocity = 0.14 m/s northeast

6 0

1 year ago

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An ice cube measuring 5.80 cm by 5.80 cm by 5.80 cm has a density of 0.917 g/mL What is the mass?

OLga [1]

Answer: 178.9 g

Explanation:

Density = $\frac{mass}{volume in mL}$

find volume of the cube: (5.80 cm) (5.80 cm) (5.80cm) = 195.112 cm³

1.0 cm³ = 1.0 mL

so 195.112 cm³ = 195.112 mL

plug value into density equation:

0.917 g/mL = (mass) / (195.112 mL)

and solve for mass!

3 0

1 year ago

The partial pressures of CH 4, N 2, and O 2 in a sample of gas were found to be 183 mmHg, 443 mmHg, and 693 mmHg, respectively.

Natasha2012 [34]

Answer:

Mole fraction N₂ = 0.336

Explanation:

Mole fraction of a gas can be determined in order to know the partial pressure of the gas, and the total pressure, in the mixture.

Total pressure in the mixture: Sum of partial pressure from all the gases

Total pressure = 183 mmHg + 443 mmHg + 693 mmHg =1319 mmHg

Mole fraction N₂ = Partial pressure N₂ / Total pressure

443 mmHg / 1319 mmHg = 0.336

Remember that mole fraction does not carry units

8 0

2 years ago

Read 2 more answers

In some chemical reactions, electrons are transferred from one substance to another, but there is no net gain or loss of electro

Natali [406]

Answer and Explanation:

The equation that depicts oxidation of neutral atom A is shown below:

$\rightarrow A^+ + e^-$

This is because one species is losing electrons due to oxidation. The species possesses positively charged after losing electrons, the magnitude of which is proportional to the number of electrons lost.

The net charge will be equivalent on both sides of the equation, too.

Therefore all other options are not correct

The equation that depicts the decline of neutral atom X is

$X + e^- \rightarrow X^-$

It is how a cell gains electrons by reduction. The species obtains a negative charge upon possessing electrons, whose magnitude is equivalent to the amount of electrons gained.

The net charge will be equivalent on both sides of the equation, too.

Therefore all other options are not correct

4 0

2 years ago

4. A sample of silicon contains 5.23 x 1011 atoms. Write this amount as a whole number.