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3 years ago

Which sentences in the passage are true?

Chemistry

1 answer:

user100 [1]3 years ago

7 0

Answer:

First and last sentence .‍♀️

Explanation:

An important thing to keep in mind about the Reading Comprehension section of the GRE as we use PowerPrep online to study is that it is just that—reading comprehension. In other words, as difficult as it may seem, and it can be pretty tricky, the test makers will always give us all the information we need in the passage to answer the question.

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Chloroform, CHCl3, reacts with chlorine, Cl2, to form carbon tetrachloride, CCl4, and hydrogen chloride, HCl. In an experiment 2

erastovalidia [21]

Answer:

Chloroform= limiting reactant

0.209mol of CCl4 is formed

And 32.186g of CCl4 is formed

Explanation:

The equation of reaction

CHCl3 + Cl2= CCl4 + HCl

From the equation 1 mol of

CHCl3 reacts with 1mol Cl2 to yield 1mol of CCl4

From the question

25g of CHCl3 really with Cl2

Molar mass of CHCl3= 119.5

Molar mass of Cl2 = 71

Hence moles of CHCl3= 25/119.5 = 0.209mol

Moles of Cl2 = 25/71 = 0.352mol

Hence CHCl3 is the limiting reactant

Since 1 mole of CHCl3 gave 1mol of CCl4

It implies that 0.209moles of CHCl3 will also give 0.209mol of CCl4

Mass of CCl4 formed = moles× molar mass= 0.209×154= 32.186g

6 0

3 years ago

You decide you want to carry a boulder home from the beach. It is 20 centimeters on each

e-lub [12.9K]

Answer:

Weight of boulder = 22,400 gram

Explanation:

Given:

Volume = 8,000 cm³

Density = 2.8

Find:

Weight of boulder

Computation:

Weight of boulder = Volume x Density

Weight of boulder = 8,000 x 2.8

Weight of boulder = 22,400 gram

3 0

3 years ago

A 2.5 L container holds a sample of hydrogen gas at 291 K and 180 kPa.

netineya [11]

Answer:

The new temperature will be 565.83 K.

Explanation:

Gay Lussac's law establishes the relationship between the temperature and the pressure of a gas when the volume is constant. This law says that the pressure of the gas is directly proportional to its temperature. This means that if the temperature increases, the pressure will increase; or if the temperature decreases, the pressure will decrease.

In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the gas temperature remains constant:

$\frac{P}{T} =k$

When an ideal gas goes from a state 1 to a state 2, it is true:

$\frac{P1}{T1} =\frac{P2}{T2}$

In this case:

P1= 180 kPa
T1= 291 K
P2= 350 kPa
T2= ?

Replacing:

$\frac{180 kPa}{291 K} =\frac{350 kPa}{T2}$

Solving:

$T2=350 kPa*\frac{291 K}{180 kPa}$

T2= 565.83 K

<u><em>The new temperature will be 565.83 K.</em></u>

6 0

3 years ago

Which of the following is the final fate of a very massive star?

STatiana [176]

D. Black holes

When a star dies out it explodes and causes a supernova and after a very long period of time the supernovas gasses vanish and the star can be visibly identified as a black hole!

8 0

3 years ago

1. A light bulb is filled with 3.54 g of argon at 25 C and 725 mmHg. What is

Ugo [173]

Answer: The volume of given gas is 2.27 L.

Explanation:

Given: Mass = 3.54 g

Temperature = $25^{o}C$ = (25 + 273) K = 298 K

Pressure = 725 mm Hg (1 mm Hg = 0.00131579) = 0.95 atm

As moles is the mass of substance divided by its molar mass.

So, moles of argon (molar mass = 40 g/mol) is as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{3.54 g}{40 g/mol}\\= 0.0885 mol$

Formula used to calculate the volume of given gas is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

$PV = nRT\\0.95 atm \times V = 0.0885 mol \times 0.0821 L atm/mol K \times 298 K\\V = 2.27 L$

Thus, we can conclude that the volume of given gas is 2.27 L.

3 0

3 years ago