Why is the average atomic mass in the periodic table a decimal?

1 answer:

4 0

Many of the atomic masses listed on the periodic table are decimal values because it's the weighted average mass of all of the isotopes of that element.

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The decomposition of dinitrogen pentoxide, N2O5, to NO2 and O2 is a first-order reaction. At 60°C, the rate constant is 2.8 × 10

Ugo [173]

Answer:

The correct option is a.

Explanation:

$2N_2O_5\rightarrow 4NO_2 + O_2$

125 kPa

125kpa - 2x 4x x

Total pressure after reaction = 176 kPa

125 kPa - 2x + 4x + x = 176 kPa

x = 17

125 kpa - 2x = 125 kPa - 2(17) = 91 kPa

Initial pressure of the dinitrogen pentoxide ,(at t=0) = $P_o= 125 kPa$

Final pressure of the dinitrogen pentoxide, (at t = t) = P = 91 kPa

The rate constant is = $k = 2.8\times 10^{-3} min^{-1}$

$t=\frac{2.303}{k}\log\frac{P_o}{P}$

$t=\frac{2.303}{2.8\times 10^{-3} min^{-1}}\log\frac{125 kPa}{91 kPa}$

$t=113.3969 minutes\approx 113 minutes$

It will take 113 minutes for the total pressure to reach 176 kPa.

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3 years ago

Moles of Zn(NO3)2 in 131.50g of this substance.

Degger [83]

<span>number of moles= mass / molecular mass
mass=131.50g
molecular mass of Zn(NO3)2 =189.39 g/mol
number of moles = 131.50 g/189.39 g/mol =0.69433 mol</span>

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Jerod used a golf club to hit a ball what was the action and reaction

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The action was him hitting the ball the reaction was the ball moving after being hit

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I need help with this

marshall27 [118]

What is it you need help on? there is nothing here????

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