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3 years ago

The atomic number of fluorine is 9. what is the mass number of a fluorine atom with 8 neutrons?

1 answer:

8 0

Mass number is found by adding the number of protons and neutrons.So Fluorine, which has 9 protons would be added to the number of neutrons, 8. Therefore, the mass number of fluorine would be 17. Hope this helps. Have a nice day.

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How many grams of hydrogen gas get produced if 10 g of aluminum reacts?

Degger [83]

Answer:

9.8

Explanation:

8 0

3 years ago

During the combustion of methane (CH4), one mole of methane gas combines with two moles of oxygen gas (O2) to produce one mole o

astraxan [27]

Answer:

CH4(g) +2O2____ CO2(g) +2H2O (l)

3 0

3 years ago

Burning 12.00 g of an oxoacid produces 17.95 g of carbon dioxide and 4.87 g of water. Consider that 0.25

Veseljchak [2.6K]

Answer: The molecular formula will be $C_6H_6O_6$

Explanation:

Mass of $CO_2$ = 17.95 g

Mass of $H_2O$ = 4.87 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 17.95 g of carbon dioxide, = $\frac{12}{44}\times 17.95=4.89g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 4.87 g of water, = $\frac{2}{18}\times 4.87=0.541g$ of hydrogen will be contained.

Mass of oxygen in the compound = (12.00) - (4.89+0.541) = 6.57 g

Mass of C = 4.89 g

Mass of H = 0.541 g

Mass of O = 6.57 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{4.89g}{12g/mole}=0.407moles$

Moles of H= $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.541g}{1g/mole}=0.541moles$

Moles of O= $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{6.57g}{16g/mole}=0.410moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{0.407}{0.407}=1$

For H = $\frac{0.541}{0.407}=1$

For O = $\frac{0.410}{0.407}=1$

The ratio of C : H : O = 1: 1 : 1

Hence the empirical formula is $CHO$ .

Hence the empirical formula is $CHO$

The empirical weight of $CHO$ = 1(12)+1(1)+1(16)= 29 g.

If 0.25 moles has mass of 44.0 g

Thus 1 mole has mass of = $\frac{44.0}{0.25}\times 1=176g$

Thus molecular mass is 176 g

Now we have to calculate the molecular formula.

$n=\frac{\text{Molecular weight }}{\text{Equivalent weight}}=\frac{176g}{29g}=6$

The molecular formula will be= $6\times CHO=C_6H_6O_6$

5 0

3 years ago

In the following overall chemical reaction, aluminum displaces chromium from chromium(III) oxide and forms aluminum oxide.

mafiozo [28]

Answer:

Change in enthalpy for the reaction is -536 kJ

Explanation:

Overall chemical reaction can be represented a summation of two given elementary steps with slight modification.
Take reaction (1a) and divide stoichiometric coefficients by 2
Take reverse reaction (2a) and divide stoichiometric coefficient by 2
Then add these two modified elementary steps to get overall chemical reaction
$\Delta H$ is an additive property. hence value of $\Delta H$ will be changed in accordance with modification

$2Al+\frac{3}{2}O_{2}\rightarrow Al_{2}O_{3}.....\Delta H_{1}=\frac{-3351.4}{2}kJ=-1675.7kJ$

$Cr_{2}O_{3}\rightarrow 2Cr+\frac{3}{2}O_{2}....\Delta H_{2}=\frac{2279.4}{2}kJ=1139.7kJ$

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$2Al+Cr_{2}O_{3}\rightarrow 2Cr+Al_{2}O_{3}....\Delta H=\Delta H_{1}+\Delta H_{2}=-1675.7+1139.7kJ=-536kJ$

6 0

3 years ago

10 points Which of these is the best example of heat transfer by radiation? *

insens350 [35]

Answer:

a) A satellite is warmed by sunlight.

Explanation:

Heat transfer by radiation mostly involves heat gain or heat loss from the Sun. In this case, Option A is the only option where sunlight is involved so it is the best example of heat transfer by radiation.

3 0

3 years ago