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3 years ago

3. What is the gram-formula mass of (NH4)3PO4?

1 answer:

4 0

The gram-formula mass means that the mass of one mole molecule. Then you just need to calculate the elements together. So the gram-formula mass of (NH4)3PO4 is equals to (14+4)*3+31+16*4= 149g/mol. So the answer is (c)

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At 25∘C, the decomposition of dinitrogen pentoxide, N2O5(g), into NO2(g) and O2(g) follows first-order kinetics with k=3.4×10−5

Annette [7]

Answer:

4600s

Explanation:

$2N_{2}O_{5}(g) - - -> 4NO_{2}(g) +O_{2}$

For a first order reaction the rate of reaction just depends on the concentration of one specie [B] and it’s expressed as:

$-\frac{d[B]}{dt}=k[B] - - - -\frac{d[B]}{[B]}=k*dt$

If we have an ideal gas in an isothermal (T=constant) and isocoric (v=constant) process.

PV=nRT we can say that P = n so we can express the reaction order as a function of the Partial pressure of one component.

$-\frac{d[P(B)]}{P(B)}=k*dt$

$-\frac{d[P(N_{2}O_{5})]}{P(N_{2}O_{5})}=k*dt$

Integrating we get:

$\int\limits^p \,-\frac{d[P(N_{2}O_{5})]}{P(N_{2}O_{5})}=\int\limits^ t k*dt$

$-(ln[P(N_{2}O_{5})]-ln[P(N_{2}O_{5})_{o})])=k(t_{2}-t_{1})$

Clearing for t2:

$\frac{-(ln[P(N_{2}O_{5})]-ln[P(N_{2}O_{5})_{o})])}{k}+t_{1}=t_{2}$

$ln[P(N_{2}O_{5})]=ln(650)=6.4769$

$ln[P(N_{2}O_{5})_{o}]=ln(760)=6.6333$

$t_{2}=\frac{-(6.4769-6.6333)}{3.4*10^{-5}}+0= 4598.414s$

4 0

3 years ago

Chemistry!! Please help!!

cluponka [151]

Answer:

4.993 ×10⁻¹¹ J

Explanation:

The nuclear binding energy is the energy equivalent to the mass defect.

The mass defect is the difference between the mass of a nucleus and the sum of the masses of its nucleons.

Calculate the mass defect

16 p = 16 × 1.007 28 u = 16.116 48 u

16 n = 16 × 1.008 67 u = 16.138 72 u

Total mass of nucleons = 32.255 20 u

- Mass of S-32 = 31.972 070 u

Mass defect = 0.283 13 u

Convert the unified atomic mass units to kilograms.

Mass defect

$= \text{0.283 13 u} \times \frac{ \text{1.66 06} \times 10^{-27} \text{ kg}}{\text{1 u}}$

$= 4.700 \times 10^{-28} \text{ kg}$

Use Einstein’s equation to convert the mass defect into energy

$E = mc^{2}$

$E = 4.7000 \times 10^{-28} \text{ kg} \times (2.998 \times 10^{8} \text{ m}\cdot\text{s}^{-1})^{2} = 4.224 \times 10^{-11} \text{ J}$

4 0

3 years ago

When a 2.5 mol of sugar (C12H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. If 2

Mademuasel [1]

Answer is: boiling point will be changed by 4°C.

Chemical dissociation of aluminium nitrate in water: Al(NO₃)₃ → Al³⁺(aq) + 3NO⁻(aq).

Change in boiling point: ΔT =i · Kb · b.

Kb - molal boiling point elevation constant of water is 0.512°C/m, this the same for both solution.

b - molality, moles of solute per kilogram of solvent., this is also same for both solution, because ther is same amount of substance.

i - Van't Hoff factor.

Van't Hoff factor for sugar solution is 1, because sugar do not dissociate on ions.

Van't Hoff factor for aluminium nitrate solution is approximately 4, because it dissociates on four ions (one aluminium cation and three nitrate anions). So ΔT is four times bigger.

6 0

3 years ago

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Sulfuric acid dissolves in water as H2SO4 2 H+(aq) + SO2 -2(aq). Which of the following solutions of H2SO4 will conduct the most

AlexFokin [52]

I believe it's 2.0 m

6 0

3 years ago

Read 2 more answers

What is the correct formula that would result from the combination of the two ionic species?

Soloha48 [4]

Answer: