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4 years ago

How does a metric prefix modify a unit?

1 answer:

7 0

Answer:Locate the row corresponding to known unit of torque along the left of the table. Multiply by the factor under the column for the desired units. For example, to convert 2 oz-in torque to n-m, locate oz-in row at table left. Locate 7.062 x 10-3 at intersection of desired n-m units column. Multiply 2 oz-in x (7.062 x 10-3 ) = 14.12 x 10-3 n-m.

Converting between units is easy if you have a set of equivalencies to work with. Suppose we wanted to convert an energy quantity of 2500 calories into watt-hours. What we would need to do is find a set of equivalent figures for those units. In our reference here, we see that 251.996 calories is physically equal to 0.293071 watt hour. To convert from calories into watt-hours, we must form a “unity fraction” with these physically equal figures (a fraction composed of different figures and different units, the numerator and denominator being physically equal to one another), placing the desired unit in the numerator and the initial unit in the denominator, and then multiply our initial value of calories by that fraction.

Explanation:

Since both terms of the “unity fraction” are physically equal to one another, the fraction as a whole has a physical value of 1, and so does not change the true value of any figure when multiplied by it. When units are canceled, however, there will be a change in units. For example, 2500 calories multiplied by the unity fraction of (0.293071 w-hr / 251.996 cal) = 2.9075 watt-hours.

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If 83.6 grams of H2 and 257 grams of N2 react, how many grams of ammonia will be produced?

SSSSS [86.1K]

The mass of ammonia that would be produced is 312.5 g

First, we will write a balanced chemical equation for the reaction

The balanced chemical equation for the reaction is

3H₂(g) + N₂(g) → 2NH₃(g)

This means

3 moles of hydrogen gas reacts with 1 mole of nitrogen gas to produce 2 moles of ammonia.

First, we will determine the number of moles of each reactant present

For Hydrogen (H₂)

Mass = 83.6 g

Molar mass = 2.016 g/mol

Using the formula

$Number\ of\ moles = \frac{Mass}{Molar\ mass}$

Number of moles of H₂ present = $\frac{83.6}{2.016}$

∴ Number of moles of H₂ present = 41.468254 moles

For Nitrogen (N₂)

Mass = 257 grams

Molar mass = 28.0134 g/mol

∴ Number of moles of N₂ present = $\frac{257}{28.0134}$

Number of moles of N₂ present = 9.174181 moles

Since,

3 moles of hydrogen gas reacts with 1 mole of nitrogen gas to produce 2 moles of ammonia

Then,

27.522543 moles of hydrogen gas will react with the 9.174181 moles of nitrogen gas to produce 18.348362 moles of ammonia

∴ 18.348362 moles of ammonia will be produced during the reaction

Now, for the mass of ammonia that would be produced

From the formula

Mass = Number of moles × Molar mass

Molar mass of ammonia = 17.031 g/mol

Mass of ammonia that would be produced = 18.348362 × 17.031

Mass of ammonia that would be produced = 312.49095 g

Mass of ammonia that would be produced ≅ 312.5 g

Hence, the mass of ammonia that would be produced is 312.5 g

Learn more here: brainly.com/question/13902065

3 0

3 years ago

A pan containing 40 grams of water was allowed to cool from a temperature of 91.0C. If the amount of heat repressed is 1,300 jou

Vinvika [58]

Answer:

83°C

Explanation:

The following were obtained from the question:

M = 40g

C = 4.2J/g°C

T1 = 91°C

T2 =?

Q = 1300J

Q = MCΔT

ΔT = Q/CM

ΔT = 1300/(4.2x40)

ΔT = 8°C

But ΔT = T1 — T2 (since the reaction involves cooling)

ΔT = T1 — T2

8 = 91 — T2

Collect like terms

8 — 91 = —T2

— 83 = —T2

Multiply through by —1

T2 = 83°C

The final temperature is 83°C

3 0

4 years ago

The number of electrons in an element x is 15 and the number of neutrons is 16. Which of the following is the correct representa

lawyer [7]

Answer:

Explanation:

A is the correct representation because mass number is 15+16=31 and atomic number is 15 which is equal to number of electrons so its 31X15

6 0

3 years ago

True or false. test tubes, spot and/or well plate will be used to combine substances in bottles and form a reaction. group of an

tresset_1 [31]

Test tubes, spot and/or well plate will be used to combine substances in bottles and form a reaction is referred to a true statement.

<h3>What is a Chemical reaction?</h3>

This is the reaction which involves substances known as reactants combining new substances which are referred to as products. This is usually done in the laboratory and equipment and tools such as test tubes, thermometer etc are used.

Test tubes, spot and/or well plate are often used to combine substances in bottles and form a reaction which must be handled with care to ensure it doesn't spill.

This is therefore the reason why the option true was chosen as the most appropriate choice.

Read more about Chemical reaction here brainly.com/question/11231920

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4 0

2 years ago

SO42- + 2Cr(OH)3 + 4OH- â†’ + 2CrO42- + 3SO32- + 5H2O

gizmo_the_mogwai [7]

Answer:

Reduced species and oxidizing agent: sulfur in the form of sulfate.

Oxidized species and reducing agent: chromium in the form of chromous hydroxide.

Explanation:

Hello!

In this case, for the reaction:

$SO_4^{2-} + 2Cr(OH)_3 + 4OH^- \rightarrow 2CrO_4^{2-} + 3SO_3^{2-} + 5H_2O$

We can see that the oxidation states of sulfur and chromium change from +6 to +4 and +3 to +6 respectively; in such a way, since the oxidized species is the same reducing agent because it undergoes an increase in the oxidation state, we infer that chromium is it as it goes from +3 to +6.

Moreover, since the reduced species is the same oxidizing agent because it undergoes a decrease in the oxidation state, we infer that sulfur is it as it goes from +6 to +4.

Best regards!

6 0

3 years ago