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To make a softball bat, a block of wood is carefully crafted into a shape that will allow a

Iteru [2.4K]

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4 0

2 years ago

Plants are responsibe for a very important energy transformation what answer

Soloha48 [4]

Plants are chlorophyll-containing photosynthetic organisms. Thus, they convert solar or radiant energy into chemical energy under the process termed as photosynthesis.

<u>Explanation:</u>

Plants are chlorophyll-containing photosynthetic living beings. Consequently, they convert radiant energy into chemical energy under the procedure named photosynthesis.

Except for remote ocean hydro-thermal environment, the sun is the only source for all biological systems on earth. Plants catch just 2-10 percent of the solar radiation and transmit it as chemical energy. All creatures are reliant for their nourishment on producers (plants), either directly or indirectly. So there is a stream of energy from the sun (radiant energy) to producers and then to consumers (chemical energy).

5 0

2 years ago

How does the tendency of iron to rust depend on ph?

mojhsa [17]

The tendency of iron to rust depend on the Ph of solution

The formation of rust increases as the PH decreases. This led agent of rusting that is oxygen gets more positive as H+ ions increase which facilitate rusting. The lower the Ph level the quick the corrosion.

6 0

2 years ago

Read 2 more answers

The gas-phase reaction follows an elementary rate law and is to be carried out first in a PFR and then in a separate experiment

astraxan [27]

Answer:

The activation energy is $=8.1\,kcal\,mol^{-1}$

Explanation:

The gas phase reaction is as follows.

$A \rightarrow B+C$

The rate law of the reaction is as follows.

$-r_{A}=kC_{A}$

The reaction is carried out first in the plug flow reactor with feed as pure reactant.

From the given,

Volume "V" = $10dm^{3}$

Temperature "T" = 300 K

Volumetric flow rate of the reaction $v_{o}=5dm^{3}s$

Conversion of the reaction "X" = 0.8

The rate constant of the reaction can be calculate by the following formua.

$V= \frac{v_{0}}{k}[(1+\epsilon )ln(\frac{1}{1-X}-\epsilon X)]$

Rearrange the formula is as follows.

$k= \frac{v_{0}}{V}[(1+\epsilon )ln(\frac{1}{1-X}-\epsilon X)]............(1)$

The feed has Pure A, mole fraction of A in feed $y_{A_{o}}$ is 1.

$\epsilon =y_{A_{o}}\delta$

$\delta$ = change in total number of moles per mole of A reacte.

$=1(2-1)=1$

Substitute the all given values in equation (1)

$k=\frac{5m^{3}/s}{10dm^{3}}[(1+1)ln \frac{1}{1-0.8}-1 \times 0.8] = 1.2s^{-1}$

Therefore, the rate constant in case of the plug flow reacor at 300K is $1.2s^{-1}$

The rate constant in case of the CSTR can be calculated by using the formula.

$\frac{V}{v_{0}}= \frac{X(1+\epsilon X)}{k(1-X)}.............(2)$

The feed has 50% A and 50% inerts.

Hence, the mole fraction of A in feed $y_{A_{o}}$ is 0.5

$\epsilon =y_{A_{o}}\delta$

$\delta$ = change in total number of moles per mole of A reacted.

$=0.5(2-1)=0.5$

Substitute the all values in formula (2)

$\frac{10dm^{3}}{5dm^{3}}=\frac{0.8(1+0.5(0.8))}{k(1-0.8)}=2.8s^{-1}$

Therefore, the rate constant in case of CSTR comes out to be $2.8s^{-1}$

The activation energy of the reaction can be calculated by using formula

$k(T_{2})=k(T_{1})exp[\frac{E}{R}(\frac{1}{T_{1}}-\frac{1}{T_{2}})]$

In the above reaction rate constant at the two different temperatures.

Rearrange the above formula is as follows.

$E= R \times(\frac{T_{1}T_{2}}{T_{1}-T_{2}})ln\frac{k(T_{2})}{k(T_{1})}$

Substitute the all values.

$=1.987cal/molK(\frac{300K \times320K}{320K \times300K})ln \frac{2.8}{1.2}=8.081 \times10^{3}cal\,mol^{-1}$

$=8.1\,kcal\,mol^{-1}$

Therefore, the activation energy is $=8.1\,kcal\,mol^{-1}$

8 0

2 years ago

Be sure to answer all parts. Fluoride ion is poisonous in relatively low amounts: 0.2 g of F− per 70 kg of body weight can cause

Stells [14]

Answer:

200 liters of fluoridated drinking water would have to be consumed by as person to reach the toxic level.

Explanation:

Toxic level of fluoride ions = 0.2 g per 70 kg body weight

Concentration of fluoride ions in drinking water = 1 mg/ L = 0.001 g/L

1 mg = 0.001 g

Let the volume of drinking water consumed by person to reach the toxic level of fluoride concentration be V.

For 70 kg body weight 0.2 grams of fluoride ions will be toxic.

$V\times 0.001 g/L=0.2 g$

$V=\frac{0.2 g}{0.001 g/L}=200 L$

200 liters of fluoridated drinking water would have to be consumed by as person to reach the toxic level.

7 0

2 years ago