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3 years ago

Which of the following numbers is correctly rounded to three significant figures, as shown in brackets?

Chemistry

1 answer:

vodomira [7]3 years ago

4 0

Answer:

D is correctly rounded to three significant figures.

Explanation:

A is incorrect because although it has 3 significant figures, it is rounded incorrectly. The correct answer would be 12,600.

B is incorrect because is rounded to 4 significant figures instead of three.

C is also incorrect because is rounded to 4 significant figures instead of three.

D is correctly rounded to three significant figures.

E is also incorrect because is rounded to 4 significant figures instead of three.

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How many moles are in 2.3x1024 g of Ag?<br> Plz help!!

ziro4ka [17]

Answer:

2.13 × 10²² moles

Explanation:

Relation between Mole and Mass is,

Mole = Mass / M.Mass

Putting values,

Mole = 2.3 × 10²⁴ g / 107.87 g/mol

Mole = 2.13 × 10²² moles

7 0

2 years ago

Ethene is converted to ethane by the reaction flows into a catalytic reactor at 25.0 atm and 250.°C with a flow rate of 1050. L/

Sphinxa [80]

Answer : The percent yield of the reaction is, 76.34 %

Explanation : Given,

Pressure of $C_2H_4$ and $H_2$ = 25.0 atm

Temperature of $C_2H_4$ and $H_2$ = $250^oC=273+250=523K$

Volume of $C_2H_4$ = 1050 L per min

Volume of $H_2$ = 1550 L per min

R = gas constant = 0.0821 L.atm/mole.K

Molar mass of $C_2H_6$ = 30 g/mole

First we have to calculate the moles of $C_2H_4$ and $H_2$ by using ideal gas equation.

For $C_2H_4$ :

$PV=nRT\\\\n=\frac{PV}{RT}$

$n=\frac{PV}{RT}=\frac{(25atm)\times (1050L)}{(0.0821L.atm/mole.K)\times (523K)}$

$n=611.34moles$

For $H_2$ :

$PV=nRT\\\\n=\frac{PV}{RT}$

$n=\frac{PV}{RT}=\frac{(25atm)\times (1550L)}{(0.0821L.atm/mole.K)\times (523K)}$

$n=902.46moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$C_2H_4+H_2\rightarrow C_2H_6$

From the balanced reaction we conclude that

As, 1 mole of $C_2H_4$ react with 1 mole of $H_2$

So, 611.34 mole of $C_2H_4$ react with 611.34 mole of $H_2$

From this we conclude that, $H_2$ is an excess reagent because the given moles are greater than the required moles and $C_2H_4$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $C_2H_6$ .

As, 1 mole of $C_2H_4$ react to give 1 mole of $C_2H_6$

As, 611.34 mole of $C_2H_4$ react to give 611.34 mole of $C_2H_6$

Now we have to calculate the mass of $C_2H_6$ .

$\text{Mass of }C_2H_6=\text{Moles of }C_2H_6\times \text{Molar mass of }C_2H_6$

$\text{Mass of }C_2H_6=(611.34mole)\times (30g/mole)=18340.2g$

The theoretical yield of $C_2H_6$ = 18340.2 g

The actual yield of $C_2H_6$ = 14.0 kg = 14000 g (1 kg = 1000 g)

Now we have to calculate the percent yield of $C_2H_6$

$\%\text{ yield of }C_2H_6=\frac{\text{Actual yield of }C_2H_6}{\text{Theoretical yield of }C_2H_6}\times 100=\frac{14000g}{18340.2g}\times 100=76.34\%$

Therefore, the percent yield of the reaction is, 76.34 %

5 0

3 years ago

Sports drinks contain sugar, salt, and flavorings dissolved in water . They can be made more or less sweet by adding different a

givi [52]

Answer:

It's a mixture.

Explanation:

Answer from Edgenuity

8 0

3 years ago

If the pressure on a 1.04 L sample of gas is doubled at constant temperature, please compute the new volume of gas: __

natulia [17]

Answer:

0.52 L.

Explanation:

Let P be the initial pressure.

From the question given above, the following data were obtained:

Initial pressure (P1) = P

Initial volume (V1) = 1.04 L

Final pressure (P2) = double the initial pressure = 2P

Final volume (V2) =?

The new volume (V2) of the gas can be obtained by using the the Boyle's law equation as shown below:

P1V1 = P2V2

P × 1.04 = 2P × V2

1.04P = 2P × V2

Divide both side by 2P

V2 = 1.04P /2P

V2 = 0.52 L

Thus, the new volume of the gas is 0.52 L.

6 0

3 years ago

What happens to the motion of molecules when temperature decreases

Juliette [100K]

Answer:

As the temperature of a solid, liquid or gas increases, the particles move more rapidly.

4 0

3 years ago

Read 2 more answers

Which of the following numbers is correctly rounded to three significant figures, as shown in brackets?​

Which of the following numbers is correctly rounded to three significant figures, as shown in brackets?