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3 years ago

THIS IS FOR MY FINAL EXAM IN CHEM!!!!!! PLEASE PLEASE PLEASE DON'T GUESS

Chemistry

1 answer:

Artemon [7]3 years ago

7 0

A. soluble.
The are solubility rules that predict precipitation reaction.

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Given the following reaction: NH4SH (s) <--> NH3 (g) + H2S (g) If we start

almond37 [142]

Answer:

D. 0.3 M

Explanation:

NH4SH (s) <--> NH3 (g) + H2S (g)

Initial concentration 0.085mol/0.25L 0 0

Change in concentration -0.2M +0.2 M +0.2M

Equilibrium 0.035mol/0.25 L=0.14M 0.2M 0.2M

concentration

Change in concentration (NH4SH) = (0.085-0.035)mol/0.25L =0.2M

K = [NH3]*[H2S]/[NH4SH] = 0.2M*0.2M/0.14M ≈ 0.29 M ≈ 0.3M

4 0

3 years ago

Which of the following is true about the concept of half-life?

Reptile [31]

Its A. because it measures the rate of the decay of the isotope

8 0

3 years ago

Read 2 more answers

5. A beam of photons with a minimum energy of 222 kJ/mol can eject electrons from a potassium surface. Estimate the range of wav

torisob [31]

Answer: The range of wavelengths of light that can be used to cause given phenomenon is $8.953 \times 10^{21} m$ .

Explanation:

Given: 222 kJ/mol (1 kJ = 1000 J) = 222000 J

Formula used is as follows.

$E = \frac{hc}{\lambda}$

where,

E = energy

h = Planck's constant = $6.625 \times 10^{-25} Js$

c = speed of light = $3 \times 10^{8} m/s$

Substitute the values into above formula as follows.

$E = \frac{hc}{\lambda}\\222000 J = \frac{6.625 \times 10^{-34}Js \times 3 \times 10^{8} m/s}{\lambda}\\\lambda = 8.953 \times 10^{21} m$

Thus, we can conclude that the range of wavelengths of light that can be used to cause given phenomenon is $8.953 \times 10^{21} m$ .

7 0

3 years ago

g Ammonium nitrate was the oxidizing agent used that damaged the New York World Trade Center in 1993 and the Federal Building in

Cloud [144]

Answer: $51.3\times 10^3$ kJ

Explanation:

The thermochemical equation for decomposition of ammonium nitrate is:

$NH_4NO_3(s)\rightarrow N_2O(g)+2H_2O(g)$ $\Delta H=-82.1kJ$

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass= 50.0 kg = $50.0\times 10^3g$ (1kg=1000g)

$\text{Number of moles of ammonium nitrate}=\frac{50.0\times 10^3g}{80g/mol}=0.625\times 10^3moles$

According to stoichiometry:

1 mole of $NH_4NO_3$ gives = 82.1 kJ of heat

Thus $0.625\times 10^3moles$ of $NH_4NO_3$ give = $\frac{82.1}{1}\times 0.625\times 10^3=51.3\times 10^3$ kJ of heat

Thus $51.3\times 10^3$ kJ of heat is evolved from the decomposition of 50.0 kg of ammonium nitrate.

7 0

3 years ago

HELPPPPPP!!!!!!!!!!!!!!!!!!<br> NEED SOME HELP PLEASE!!!!!!!!!!!

Sergio039 [100]

Answer:

second

convection current

first

lithosphere

Explanation:

xoxo

Demi

3 0

4 years ago