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2 years ago

In what direction is the universe

Chemistry

1 answer:

svetoff [14.1K]2 years ago

5 0

B.expanding out from the center

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Using the equation below, calculate the number of grams of H2O that are formed from the reaction of 34.0 g of NH3.

Mumz [18]

Answer:

54 grams of H₂O

Explanation:

4NH₃ + 3O₂ → 2N₂ + 6H₂O

Ratio is 4:6.

Let's convert the mass of ammonia in moles

Mass / Molar mass = Mol

34 g / 17 g/m = 2 moles

If 4 moles of ammonia are needed to produce 6 mol of water

2 mol of NH₃ will produce ( 2 .6 )/4 = 3 moles

Molar mass water = 18 g/m

Mass = mol . molar mass → 3 m . 18 g/m = 54 grams

8 0

3 years ago

Hydrogen-3 has a half-life of 12.32 years. A sample of H-3 weighing 3.02 grams is left for 15.0 years. What will the final weigh

kaheart [24]

Answer:

$\large \boxed{\text{1.38 g}}$

Explanation:

Two important formulas in radioactive decay are

$(1) \qquad t_{\frac{1}{2}} = \dfrac{\ln 2}{k}\\\\(2) \qquad \ln \left(\dfrac{N_{0}}{N}\right) = kt$

1. Calculate the decay constant k

$\begin{array}{rcl}t_{\frac{1}{2}} &=& \dfrac{\ln 2}{k}\\\\\text{12.32 yr} &= &\dfrac{\ln 2}{k}\\\\k & = & \dfrac{\ln 2}{\text{12.32 yr}}\\\\& = & \text{0.056 26 yr}^{-1}\\\end{array}$

2. Calculate the mass remaining

$\begin{array}{rcl}\ln \left(\dfrac{A_{0}}{A}\right) &= &kt \\\\\ln \left(\dfrac{\text{3.20 g}}{A}\right) &= &\text{0.056 26 yr}^{-1}\times \text{15 yr} \\\\\ln \left(\dfrac{\text{3.20 g}}{A}\right) &= &0.8439 \\\\\dfrac{\text{3.20 g}}{A} &= &e^{0.8439} \\\\\dfrac{\text{3.20 g}}{A}&= &2.325 \\\\A &= &\dfrac{\text{3.20 g}}{2.325}\\\\&= & \textbf{1.38 g}\\\end{array}\\\text{The final mass of the sample will be $\large \boxed{\textbf{1.38 g}}$}$

8 0

3 years ago

3. Why have we not been able to create a fusion reactor on Earth?

katrin2010 [14]

Answer:

We are not able to create a fusion reactor on Earth because fusion energy production is not based on a chain reaction, as is fission. Plasma must be kept at very high temperatures with the support of external heating systems and confined by an external magnetic field.

Explanation:

7 0

3 years ago

Read 2 more answers

Which of the following shows a valid combustion reaction?

marta [7]

Answer: C2H4 + 3O2 → 2CO2 + 2H2O

Explanation:

2Al + 2O2 → 2AlO + O2 Not Balanced Properly: 2Al + O2 = 2AlO

C2H4 + 3O2 → 2CO2 + 2H2O Looks Good

2CH4 + O2 → 2CO + 4H2 Not Correct: CO should be CO2

Ca + O2 → CaOH Not Balanced and No source for the H