All categories

3 years ago

How many grams of mgo are produced during an enthalpy change of -231 kj ?

Chemistry

1 answer:

SCORPION-xisa [38]3 years ago

3 0

The reaction for the formation of MgO(s):

2 Mg (s) + O2(g) -à 2MgO(s) ΔH = -601.24 kJ/mol

<span>The enthalpy information is taken from: http://webbook.nist.gov/cgi/inchi?ID=C1309484&Mask=2</span>

From the equation and with an enthalpy change of -231 kJ:

-231 kJ * 2 mol Mg * (1/-601.24 kJ/mol) = 0.76841 mol Mg

Then, with the molar mass of MgO = 40.3,

0.76841 mol Mg *(2 mol MgO/2 mol Mg)* 40.3 g/mol MgO = <span>30.967 g MgO</span>

You might be interested in

Burka [1]

Answer:

$\large \boxed{\text{E) 721 K; B) 86.7 g}}$

Explanation:

Question 7.

We can use the Combined Gas Laws to solve this question.

a) Data

p₁ = 1.88 atm; p₂ = 2.50 atm

V₁ = 285 mL; V₂ = 435 mL

T₁ = 355 K; T₂ = ?

b) Calculation

$\begin{array}{rcl}\dfrac{p_{1}V_{1}}{T_{1}}& =&\dfrac{p_{2}V_{2}}{T_{2}}\\\\\dfrac{1.88\times285}{355} &= &\dfrac{2.50\times 435}{T_{2}}\\\\1.509& = &\dfrac{1088}{T_{2}}\\\\1.509T_{2} & = & 1088\\T_{2} & = & \dfrac{1088}{1.509}\\\\ & = & \textbf{721K}\\\end{array}\\\text{The gas must be heated to $\large \boxed{\textbf{721 K}}$}$

Question 8. I

We can use the Ideal Gas Law to solve this question.

pV = nRT

n = m/M

pV = (m/M)RT = mRT/M

a) Data:

p = 4.58 atm

V = 13.0 L

R = 0.082 06 L·atm·K⁻¹mol⁻¹

T = 385 K

M = 46.01 g/mol

(b) Calculation

$\begin{array}{rcl}pV & = & \dfrac{mRT}{M}\\\\4.58 \times 13.0 & = & \dfrac{m\times 0.08206\times 385}{46.01}\\\\59.54 & = & 0.6867m\\m & = & \dfrac{59.54}{0.6867 }\\\\ & = & \textbf{86.7 g}\\\end{array}\\\text{The mass of NO$_{2}$ is $\large \boxed{\textbf{86.7 g}}$}$

7 0

3 years ago

Equal masses of water undergo condensation, deposition, evaporation, and sublimation. a) Which process releases the most energy?

Artemon [7]

Answer:

A. Condensation

B. Evaporation

Explanation:

Condensation releases energy when water vapor condenses to form water droplets. Evaporation absorbs energy whenever it changes from liquid to gas, the heat from the sun heats the water up and absorbs energy.

6 0

3 years ago

Please help me out Fast people

kifflom [539]

I think convergent but could be wrong

4 0

4 years ago

Read 2 more answers

Which groups of the periodic table want to gain electrons? What kind(s) of elements are these groups

lukranit [14]

Answer:

Elements that are metals tend to lose electrons and become positively charged ions called cations. Elements that are nonmetals tend to gain electrons and become negatively charged ions called anions. Metals that are located in column 1A of the periodic table form ions by losing one electron.

Explanation:

6 0

3 years ago

what has 4 valence electrons, shows properties of metals and non metals, and has 32 protons in the nucleus of each atom

12345 [234]

Here is your answer

$\bold{Germanium}$

REASON:

Elements which have 4 valence electrons are generally metalloids.

The metalloids show the properties of both metals and non-metals.

We know that,

no. of protons= Atomic number

So,

Atomic no.= 32

Hence,

The element is Germanium which is a metalloid with 4 valence electrons and has 32 protons in nucleus of each atom because it has atomic no. 32

HOPE IT IS USEFUL

6 0

3 years ago