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3 years ago

Any help with these questions would help i'm lost

Chemistry

1 answer:

SSSSS [86.1K]3 years ago

5 0

Answer:

1. 31.25 mL

2. 1.98 g/L

3. 0.45 g/mL

Explanation:

For each of the problems, you need to perform unit conversions. You need to use the information given to you to convert to a specific unit.

1. You need volume (mL). You have density (g/mL) and mass (g). Divide mass by density. You will cancel out mL and be left with g.

(50.0 g)/(1.60 g/mL) = 31.25 mL

2. You are given grams and liters. You need to find density with units g/L. This means that you have to divide grams by liters.

(0.891 g)/(0.450 L) = 1.98 g/L

3. You have to find density again but this time with units g/mL. Divide the given mass by the volume.

(10.0 g)/(22.0 mL) = 0.45 g/mL

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45.3 in. to millimeters

Stels [109]

1,150.62 millimeters

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3 years ago

How many moles are in a 12.0 g sample of NiC12

Nady [450]

Answer:

0.17 moles

Explanation:

In the elements of the periodic table, the atomic mass = molar mass. Ex: Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.

In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:

Molar Mass of Ni (Nickel): 58.69 g/mol

Molar Mass of C (Carbon): 12.01 g/mol

Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.

58.69 g/mol of Nickel + 12.01 g/mol of Carbon = 70.7 g/mol of NiC-12

There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:

12g NiC-12 (1 mol of NiC-12/70.7g NiC-12) = 0.17 mol of NiC-12
The grams cancel, leaving us with moles of NiC-12, so the answer is 0.17 moles of NiC-12 in a 12 g sample.

P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.

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3 years ago

What is the density of CHCL3 vapor at 1.00atm and 298K?

Advocard [28]

Answer:

4.8 g/mL is the density of chloroform vapor at 1.00 atm and 298 K.

Explanation:

By ideal gas equation:

$PV=nRT$

Number of moles (n)

can be written as: $n=\frac{m}{M}$

where, m = given mass

M = molar mass

$PV=\frac{m}{M}RT\\\\PM=\frac{m}{V}RT$

where,

$\frac{m}{V}=d$ which is known as density of the gas

The relation becomes:

$PM=dRT$ .....(1)

We are given:

M = molar mass of chloroform= 119.5 g/mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the gas = $298K$

P = pressure of the gas = 1.00 atm

Putting values in equation 1, we get:

$1.00atm\times 119.5g/mol=d\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 298K\\\\d=4.88g/L$

4.8 g/mL is the density of chloroform vapor at 1.00 atm and 298 K.

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3 years ago

What is the primary reason that atomic radius decreases as you move from left to right across the periodic table even through th

Anika [276]

Answer:

As you move across a period the electrons are being added to the same shell. But, protons are being added as well. This makes the nucleus more positively charged and, increasing protons has a greater effect than electrons. So, there is a greater nuclear attraction and, because the electrons are being added to the same shell that shell gets pulled in more. This causes a decrease in atomic radius.

Explanation:

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3 years ago

An ax is used to chop wood. The metal part chops through the wood, pushing it apart into two smaller sections. which simple mach

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4 years ago