NEED ASAP!!! Several samples of a solid was measured to have these masses and volumes listed in the

Aluminum has a density of 2.70 g/m. Calculate the mass (in grams) of a piece of aluminum having a volume of 382 mL

Natalka [10]

The aluminum has a mass of 1031.4 grams.

8 0

3 years ago

Butane (C4 H10(g), Hf = –125.6 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Hf = –393.5 kJ/mol ) and water (H2 O,

WITCHER [35]

Answer: Enthalpy of combustion (per mole) of $C_4H_{10} (g)$ is -2657.5 kJ

Explanation:

The chemical equation for the combustion of butane follows:

$2C_4H_{10}(g)+4O_2(g)\rightarrow 8CO_2(g)+10H_2O(g)$

The equation for the enthalpy change of the above reaction is:

$\Delta H^o_{rxn}=[(8\times \Delta H^o_f_{CO_2(g)})+(10\times \Delta H^o_f_{H_2O(g)})]-[(1\times \Delta H^o_f_{C_4H_{10}(g)})+(4\times \Delta H^o_f_{O_2(g)})]$

We are given:

$\Delta H^o_f_{(C_4H_{10}(g))}=-125.6kJ/mol\\\Delta H^o_f_{(H_2O(g))}=-241.82kJ/mol\\\Delta H^o_f_{(O_2(g))}=0kJ/mol\\\Delta H^o_f_{(CO_2(g))}=-393.5kJ/mol\\\Delta H^o_{rxn}=?$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(8\times -393.5)+(10\times -241.82)]-[(2\times -125.6)+(4\times 0)]\\\\\Delta H^o_{rxn}=-5315kJ$

Enthalpy of combustion (per mole) of $C_4H_{10} (g)$ is -2657.5 kJ

6 0

3 years ago

what is the mole fraction of neon in a mixture that contains 0.628 g of helium, 11.491 g of neon, and 7.613 g of argon?

VMariaS [17]

Answer:

0.2

Explanation:

Given parameters:

Mass of helium = 0.628g

Mass of neon = 11.491g

Mass of argon = 7.613g

Unknown:

Mole fraction of neon = ?

Solution:

The mole fraction of an element is the number of moles of that element to the total number of moles in the gas mixture.

We need to calculate the number of moles of each element first;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Helium = 4g/mol

Molar mass of Neon = 20g/mol

Molar mass of Argon = 40g/mol

Number of moles of He = $\frac{0.628}{4}$ = 0.16moles

Number of moles of Ne = $\frac{11.491}{20}$ = 0.58moles

Number of moles of Ar = $\frac{7.613}{40}$ = 0.19moles

Total number of moles = 0.16moles + 0.58moles + 0.19moles = 0.93moles

Mole fraction Neon = $\frac{0.19}{0.93}$ = 0.2

4 0

3 years ago

There are three bulbs powered by a battery. What will happen if the middle light burns out.

Vadim26 [7]

Answer:

nuclear war ;P

Explanation:

8 0

3 years ago

Table salt is a refined salt containing about 97 to 99% sodium Chloride iodized salt containing potassium iodide is widely avail

Free_Kalibri [48]

Answer:

Explanation:

Sodium chloride is ionic compound. It is formed by the transfer of electron from one atom to the atom of another element.

Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.

The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.

Sodium atom have one valance electron by losing this one valance electron sodium atom get the complete octet. Chlorine atom has seven valance electrons and needed to lose seven valance electrons or to get one electron and thus complete the octet. It is very easy for chlorine atom to get one electrons instead of losing all seven electron. Thus when it react with sodium it gain the valance electron of sodium and form ionic compound.

That's why only one atom of sodium combine with one atom chlorine.

8 0

3 years ago