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3 years ago

1. Which of the following does NOT indicate that a chemical change may have taken place?

Chemistry

1 answer:

mojhsa [17]3 years ago

8 0

A fracture Formation .
A matter is neither destroyed or created

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Find the volume of 6.45 moles of gas present at a temperature of 27.0oC and a pressure of 675 torr.

maw [93]

<u>Answer:</u> The volume of the gas is 178.76 L

<u>Explanation:</u>

The ideal gas equation is given as:

.......(1)

where

P = pressure of the gas = 675 torr

V = volume of gas = ?

n = number of moles of gas = 6.45 moles

R = Gas constant = 62.36 L.torr/mol.K

T = temperature of the gas = $27^oC=[27+273]K=300K$

Putting values in equation 1, we get:

$675torr\times V=6.45mol\times 62.36L.torr/mol.K\times 300K\\\\V=\frac{6.45\times 62.36\times 300}{675}=178.76 L$

Hence, the volume of the gas is 178.76 L

3 0

3 years ago

At constant temperature and pressure, 5.0 L of SO2 is

Ne4ueva [31]

I've done this a few times and keep coming up with 5.0 L . I used the mole ratio, and SO 2 as the LR. That would make 2 moles of SO3 5.0 L but its not one of your choices. the temp and pressure are constant, so according to n/v = p/rt the volume is the same as the moles. hope this helps

4 0

3 years ago

The density of concentrated ammonia, which is 28.0% w/w nh3, is 0.899 g/ml. what volume of this reagent should be diluted to 1.0

vlada-n [284]

Answer: 2.4 ml

Solution :

Molar mass of $NH_3$ = 17 g/mole

Given,: 28% w/w of $NH_3$ solution means 28 g of ammonia in 100 g of solution.

Mass of solution = 100 g

Now we have to calculate the volume of solution.

$Volume=\frac{Mass}{Density}=\frac{100g}{0.899g/ml}=111.2ml$

Molarity : It is defined as the number of moles of solute present in one liter of solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute $NH_3=\frac{\text {given mass}}{\text {molar mass}}=\frac{28}{17}=1.65moles$

$V_s$ = volume of solution in liter = 0.11 L

Now put all the given values in the formula of molarity, we get

$Molarity=\frac{1.65moles}{0.11L}=15mole/L$

Using molarity equation:

$M_1V_1=M_2V_2$

$15\times V_1=0.036\times 1.0\times 10^{3}$

$V_1=2.4ml$

6 0

3 years ago

After undergoing alpha decay, an atom of radium-226 becomes

Zanzabum

The answer is b. radon-222. The alpha decay means that it will emit an alpha particle when decays. The alpha particle has two protons and two neutrons. So Radium(88) minus two protons will become Radon(86). And the atomic mass will become 226-4=222.

8 0

2 years ago

A sample of a compound contains 3.21 g of sulfur and 11.4 g of fluorine. Which of the following represents the empirical formula

Sergeeva-Olga [200]

Answer:

The empirical formula is SF6 (option E)

Explanation:

Step 1: Data given

Mass of sulfur = 3.21 grams

Mass of fluorine = 11.4 grams

Molar mass sulfur = 32.065 g/mol

Molar mass fluorine = 19.00 g/mol

Step 2: Calculate moles

Moles = mass /molar mass

Moles sulfur = 3.21 grams / 32.065 g/mol

Moles sulfur = 0.100 moles

Moles fluorine = 11.4 grams / 19.00 g/mol

Moles fluorine = 0.600 moles

Step 3: Calculate mol ratio

We divide by the smallest amount of moles

S: 0.100 / 0.100 = 1

F : 0.600 / 0.100 = 6

The empirical formula is SF6 (option E)

7 0

3 years ago