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3 years ago

Make the following conversion. 120 mL = _____ cm³ 12.0 1200 120 1.20

Chemistry

2 answers:

r-ruslan [8.4K]3 years ago

5 0

Answer: 120

Explanation:

Volume of the gas is defined as the space occupied by a substance. It is expressed in units like $cm^3$ , $m^3$ , L and ml.

All these units of volume are inter convertible.

We are given:

Volume of the gas = $120ml$

Converting this unit of volume into $cm^3$ by using conversion factor:

$1cm^3=1ml$

$120ml=\frac{1}{1}\times 120=120cm^3$

Thus the volume in $cm^3$ would be 120.

Lina20 [59]3 years ago

4 0

The correct answer would be 120.

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DedPeter [7]

Answer:

Lithium has 3 protons, 4 neutrons, 3 electrons, and its mass is 6.941 u

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3 years ago

How many formula units make up 24.2 g of magnesium chloride (MgCl2)?<br><br> Help!!

NNADVOKAT [17]

Answer:

Approximately $1.53 \times 10^{23}$ formula units ( $0.254\; \rm mol$ ).

Explanation:

Refer to a modern periodic table for the relative atomic mass of magnesium ( $\rm Mg$ ) and chlorine ( $\rm Cl$ ):

$\rm Mg$ : $24.305$ .
$\rm Cl$ : $35.45$ .

In other words, the mass of $1\; \rm mol$ of $\rm Mg$ atoms would be (approximately) $24.305\; \rm g$ .

Likewise, the mass of $1\; \rm mol$ of $\rm Cl$ atoms would be approximately $35.45\; \rm g$ .

One formula unit of the ionic compound $\rm MgCl_{2}$ includes exactly as many atoms as there are in the given formula. The formula mass of a compound is the mass of $1\; \rm mol$ of the formula units of this compound.

The formula $\rm MgCl_{2}$ includes one $\rm Mg$ atom and two $\rm Cl$ atoms.

Hence, every formula unit of $\rm MgCl_{2} \!$ would include the same number of atoms: one $\rm Mg\!$ atom and two $\rm Cl\!$ atoms. There would be $1\; \rm mol$ of $\rm Mg$ atoms and $2\; \rm mol$ of $\rm Cl$ atoms in $1\; \rm mol\!$ of $\rm MgCl_{2}$ formula units.

Thus, the mass of $1\; \rm mol\!$ of $\rm MgCl_{2}$ formula units would be equal to the mass of $1\; \rm mol$ of $\rm Mg$ atoms plus the mass of $2\; \rm mol$ of $\rm Cl$ atoms. (The mass of $1\; \rm mol\!\!$ of each atom could be found from the relative atomic mass of each element.)

$\begin{aligned}& M({\rm MgCl_{2}}) \\ =\; & 24.305\; {\rm g \cdot mol^{-1}} + 2\times {\rm 35.45 \; \rm g \cdot mol^{-1}} \\ =\; & 95.205\; \rm g \cdot mol^{-1}\end{aligned}$ .

In other words, the formula mass of $\rm MgCl_{2}$ is $95.205\; \rm g \cdot mol^{-1}$ .

Therefore, the number of formula units in $m = 24.2\; \rm g$ of $\rm MgCl_{2}$ would be:

$\begin{aligned}n &= \frac{m({\rm MgCl_{2}})}{M({\rm MgCl_{2}})} \\ &= \frac{24.2\; \rm g}{95.205\; \rm g\cdot mol^{-1}} \\ & \approx 0.254\; \rm mol\end{aligned}$ .

Multiple $n$ by Avogadro's Number $N_{A} \approx 6.022 \times 10^{23}\; \rm mol^{-1}$ to estimate the number of formula units in $0.254\; \rm mol$ :

$\begin{aligned}N &= n \cdot N_{A} \\ &\approx 0.254\; \rm mol \times 6.022 \times 10^{23}\; \rm mol^{-1} \\ &\approx 1.53\times 10^{23}\end{aligned}$ .

6 0

3 years ago

How much heat is released when 75 g of octane is burned completely if the enthalpy of combustion is -5,500 kJ/mol CsH18? C8H18 +

aalyn [17]

Answer : The correct option is, (D) 3600 kJ

Explanation :

Mass of octane = 75 g

Molar mass of octane = 114.23 g/mole

Enthalpy of combustion = -5500 kJ/mol

First we have to calculate the moles of octane.

$\text{ Moles of octane}=\frac{\text{ Mass of octane}}{\text{ Molar mass of octane}}=\frac{75g}{114.23g/mole}=0.656moles$

Now we have to calculate the heat released in the reaction.

As, 1 mole of octane released heat = -5500 kJ

So, 0.656 mole of octane released heat = 0.656 × (-5500 kJ)

= -3608 kJ

≈ -3600 kJ

Therefore, the heat released in the reaction is 3600 kJ

5 0

3 years ago

1. Ibuprofen (C13H18O2) is the active ingredient in many nonprescription pain relievers. Each tablet contains 200 mg of ibuprofe

Dmitry_Shevchenko [17]

Answer :

The molar mass of ibuprofen is, 206.29 g/mole.

The number of moles of ibuprofen in a single tablet is, 0.000969 moles

The number of moles of ibuprofen in four doses is, 0.007752 moles

Solution : Given,

Molar mass of carbon = 12.01 g/mole

Molar mass of hydrogen = 1.01 g/mole

Molar mass of oxygen = 15.99 g/mole

1) Now we have to calculate the molar mass of ibuprofen.

Molar mass of ibuprofen, $C_{13}H_{18}O_2$ = $(13\times 12.01)+(18\times 1.01)+(2\times 15.99)=206.29g/mole$

The molar mass of ibuprofen = 206.29 g/mole

2) Now we have to calculate the moles of ibuprofen.

Formula used : $Moles=\frac{Mass}{\text{ Molar mass}}$

Given : Mass of ibuprofen = 200 mg = 0.2 g (1 mg = 1000 g)

$\text{ Moles of ibuprofen}=\frac{\text{ Mass of ibuprofen}}{\text{ Molar mass of ibuprofen}}=\frac{0.2g}{206.29g/mole}=0.000969moles$

The moles of ibuprofen = 0.000969 moles

3) Now we have to calculate the number of moles of ibuprofen for four doses.

Number of tablets in one dose = 2

Total number of tablets in 4 doses = 4 × 2 = 8

Number of moles of ibuprofen in 8 tablets =

$\text{ Number of moles of ibuprofen in 1 tablet}\times \text{ Total number of tablets}=0.000969\times 8=0.007752moles$

6 0

3 years ago

Read 2 more answers

Suppose you need to prepare 136.9 mL of a 0.315 M aqueous solution of NaCl.

Varvara68 [4.7K]

Answer:

2.52 g NaCl

Explanation:

(Step 1)

To find the mass, you first need to find the moles NaCl. This value can be found using the molarity ratio:

Molarity = moles / volume (L)

After you convert mL to L, you can plug the given values into the equation and simplify to find moles.

136.9 mL / 1,000 = 0.1369 L

Molarity = moles / volume

0.315 M = moles / 0.1369 L

0.0431 = moles

(Step 2)

Now, you can use the molar mass to convert moles to grams.

Molar Mass (NaCl): 22.990 g/mol + 35.453 g/mol

Molar Mass (NaCl): 58.443 g/mol

0.0431 moles NaCl 58.443 g
------------------------------ x ------------------- = 2.52 g NaCl
1 mole

4 0

2 years ago