Atomic mass of 14.01 amu

What compound do the ions Al3+ and O2- form

Mars2501 [29]

Hey

the answer is going to be

AL3 plus and O2 negative will form Aluminum Oxide. It has manynames such as corundum and alumina. It is an amphoteric oxide.

8 0

3 years ago

A bomb calorimeter has a heat capacity of 675 J/°C and contains 925 g of water. If the combustion of 0.500 mole of a hydrocarbon

ikadub [295]

Answer: The enthalpy of the reaction is 269.4 kJ/mol

Explanation:

To calculate the heat absorbed by the calorimeter, we use the equation:

$q_1=c\Delta T$

where,

q = heat absorbed

c = heat capacity of calorimeter = 675 J/°C

$\Delta T$ = change in temperature = $T_2-T_1=(53.88-24.26)^oC=29.62^oC$

Putting values in above equation, we get:

$q_1=675J/^oC\times 29.62^oC=19993.5J$

To calculate the heat absorbed by water, we use the equation:

$q_2=mc\Delta T$

where,

q = heat absorbed

m = mass of water = 925 g

c = heat capacity of water = 4.186 J/g°C

$\Delta T$ = change in temperature = $T_2-T_1=(53.88-24.26)^oC=29.62^oC$

Putting values in above equation, we get:

$q_2=925g\times 4.186J/g^oC\times 29.62^oC=114690.12J$

Total heat absorbed = $q_1+q_2$

Total heat absorbed = $[19993.5+114690.12]J=134683.62J=134.7kJ$

To calculate the enthalpy change of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

q = amount of heat absorbed = 134.7 kJ

n = number of moles of hydrocarbon = 0.500 moles

$\Delta H_{rxn}$ = enthalpy change of the reaction

Putting values in above equation, we get:

$\Delta H_{rxn}=\frac{134.7kJ}{0.500mol}=269.4kJ/mol$

Hence, the enthalpy of the reaction is 269.4 kJ/mol

6 0

4 years ago

Read 2 more answers

How many molecules of co2 are in a 500. 0 ml container at 780 mm hg and 135°c? 8. 76 × 1021 molecules 9. 23 × 1021 molecules 5.

Aloiza [94]

Step 1:

ok we have to use the formula PV=nRT

p=Pressure (must be converted to atm)= 780 mmHg

1 amt= 760 mmHg use this as a conversion factor

780 mmHg (1 atm/760 mmHg)= 1.026

V= Volume= 5.00 mL = o.5 L

n=number of moles which we have to find first

R= 0.0821

T(convert to Kelvins by adding 273.15 to the celsius temperature)= 135 C + 273.15= 408.15 k

Now plug in->

(1.026 atm)(o.5 L)= n(0.0821)(408.15 K)

(1.026 atm)(0.5 L)= n(33.509115)

(0.513)= n(33.509115)

n(number of moles)= 0.01532 mol

Now we have to convert to moles using Avagodro's number which states that 1 mol = 6.022 x 10^23 molecules or atoms

So 0.01532 mol (6.022 x 10^23 number of molesules)/ (1 mol) = 9.225704 x 10^21 = 9.226 x 10^21 colecules

Step 2

You must transfer pressure into pascals, 780 mm Hg = 103991 Pa

135*C = 408.15 k

then from the equation pV = nRt

n = pV / RT (T in Kelvins, V in M^3)

n = 103991 x 500 x 10^-6 / (8.314 x 408.15)= 0.015322 moles of N2

1 mol of everything is 6.022 x 10^23 particles, so 0.15322 moles is 0.15322 x 6.022 x 10^23 = 9.2269084 x 10^21 molecules

Explanation:

Hope this helps :)

5 0

2 years ago

A 0.67 gram sample of chromium is reacted with sulfur. The resulting chromium sulfide has a mass of 1.2888 grams. What is the em

spin [16.1K]

Answer:

Cr₂S₃

Explanation:

From the question given above, the following data were obtained:

Mass of chromium (Cr) = 0.67 g

Mass of chromium sulfide = 1.2888 g

Empirical formula =?

Next, we shall determine the mass of sulphur (S) in the compound. This can be obtained as follow:

Mass of chromium (Cr) = 0.67 g

Mass of chromium sulfide = 1.2888 g

Mass of sulphur (S) =?

Mass of S = (Mass of chromium sulfide) – (Mass of Cr)

Mass of S = 1.2888 – 0.67

Mass of S = 0.6188 g

Finally, we shall determine the empirical formula of the compound. This can be obtained as follow:

Mass of Cr = 0.67 g

Mass of S = 0.6188 g

Divide by their molar mass

Cr = 0.67 / 52 = 0.013

S = 0.6188 / 32 = 0.019

Divide by the smallest

Cr = 0.013 / 0.013 = 1

S = 0.019 / 0.013 = 1.46

Multiply by 2 to express in whole number

Cr = 1 × 2 = 2

S = 1.46 × 2 = 3

Therefore, the empirical formula of the compound is Cr₂S₃

5 0

3 years ago

Which is the most likely to be reduced?

NISA [10]

Answer : The correct option is, $Zn^{2+}$

Explanation :

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. That means, the loss of electrons takes place.

Or we can say that, oxidation reaction occurs when a reactant losses electrons in the reaction.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. That means, the gain of electrons takes place.

Or we can say that, reduction reaction occurs when a reactant gains electrons in the reaction.

According to the electrochemical series, $Zn^{2+}$ most likely to be reduced because

Hence, the ion most likely to be reduced is $Zn^{2+}$ .

3 0

3 years ago