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3 years ago

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In nature, oxygen has three common isotopes. The atomic masses and relative abundances of these isotopes are given in the table

below.
Isotope Atomic Mass (amu) Relative Abundance
O-16 15.995 99.759%
O-17 16.995 0.037%
O-18 17.999 0.204%
Calculate the average atomic mass of oxygen. Show all of your calculations below.

1 answer:

Reil [10]3 years ago

7 0

<span>15.995* 0.99759 + 16.995*0.00037 + 17.999*0.00204 = 15.999</span>

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2 years ago

Water flows from the bottom of a large tank where the pressure is 100 psig through a pipe to a turbine which produces 5.82 hp. T

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Explanation:

Bernoulli equation for the flow between bottom of the tank and pipe exit point is as follows.

$\frac{p_{1}}{\gamma} + \frac{V^{2}_{1}}{2g} + z_{1}$ = $\frac{p_{2}}{\gamma} + \frac{V^{2}_{2}}{2g} + z_{2} + h_{f} + h_{t}$

$\frac{(100 \times 144)}{62.43} + 0 + h[tex] = [tex]\frac{(50 \times 144)}{(62.43)} + \frac{(70)^{2}}{2(32.2)} + 0 + 40 + 60$

h = $\frac{(50 \times 144)}{(62.43)} + \frac{(70)^{2}}{2(32.2)} + 40 + 60 - \frac{(100 \times 144)}{(62.43)}$

= 60.76 ft

Hence, formula to calculate theoretical power produced by the turbine is as follows.

P = mgh

= $100 \times 60.76$

= 6076 lb.ft/s

= 11.047 hp

Efficiency of the turbine will be as follows.

$\eta_{t}$ = $\frac{P_{actual}}{P_{theoretical}}$ × 100%

= $\frac{5.82}{11.047} \times 100%$

= 52.684%

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3 years ago

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3 years ago

Determine the rate law, including the values of the orders and rate law constant, for the following reaction using the experimen

olga55 [171]

Answer: Rate law= $k[A]^1[B]^2$ , order with respect to A is 1, order with respect to B is 2 and total order is 3. Rate law constant is $3L^2mol^{-2}s^{-1}$

Explanation: Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

$Rate=k[A]^x[B]^y$

k= rate constant

x = order with respect to A

y = order with respect to A

n = x+y = Total order

a) From trial 1: $1.2\times 10^{-2}=k[0.10]^x[0.20]^y$ (1)

From trial 2: $4.8\times 10^{-2}=k[0.10]^x[0.40]^y$ (2)

Dividing 2 by 1 : $\frac{4.8\times 10^{-2}}{1.2\times 10^{-2}}=\frac{k[0.10]^x[0.40]^y}{k[0.10]^x[0.20]^y}$

$4=2^y,2^2=2^y$ therefore y=2.

b) From trial 2: $4.8\times 10^{-2}=k[0.10]^x[0.40]^y$ (3)

From trial 3: $9.6\times 10^{-2}=k[0.20]^x[0.40]^y$ (4)

Dividing 4 by 3: $\frac{9.6\times 10^{-2}}{4.8\times 10^{-2}}=\frac{k[0.20]^x[0.40]^y}{k[0.10]^x[0.40]^y}$

$2=2^x,2=2^1$ , x=1

Thus rate law is $Rate=k[A]^1[B]^2$

Thus order with respect to A is 1 , order with respect to B is 2 and total order is 1+2=3.

c) For calculating k:

Using trial 1: $1.2\times 10^{-2}=k[0.10]^1[0.20]^2$

$k=3 L^2mol^{-2}s^{-1}$ .

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3 years ago

Why the mass of a rusted nail is greater then the nail before it rusted?

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This is the reaction formula,
4Fe+3O2=2Fe2O3
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3 years ago