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3 years ago

Why do metals change in appearance over time?

1 answer:

5 0

The exterior surface of metal can be changed by many chemical reaction takes place the reaction is carried out by presence of oxygen and water in air which Demage shiny surface of metal. The other processes can also be involved as pollution, moisture and environmental change can also effect on the surface of metal.

If metal is keept in open environment for a long time moisture contents in air boats the corrosion and rusting of metal processes.

Hopefully you will understand.

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PLEASE HELP ME!!!! Which energy graph represents the nonspontaneous transition of graphite into diamond?

Viefleur [7K]

Answer:

A picture .There is high reactions in progression still the energy reaction reduced to indicate complete reaction.

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2 years ago

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amoun

Dennis_Churaev [7]

Answer:

dG will be the same -20 kcal/mol

Explanation:

The dG can be expressed in terms of the G(products) - G(reactants). If the amount of enzyme is doubled the Gibbs energy of the reactants and products will be the same, so the substraction dG has the same value

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3 years ago

Consider the nuclear equation below.

Dovator [93]

Answer:

its NOT C

Explanation:

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3 years ago

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ASAP! Choose all that apply. Which of the following chemicals are utilized in modern medicine? NaCl Ba N 2O Si C 14H 10O 4 H 2S

Zinaida [17]

Answer:

14 H i think , but i believe that thats the answer

4 0

2 years ago

Read 2 more answers

Given the following: [G3P] = 1.5x10-5M; [BPG] = 3.0x10-3M ; [NAD+] = 1.2x10-5M; [NADH]=1.0x10-4 ; [HPO42-]= 1.2x10-5 M; pH = 7.5

mel-nik [20]

<u>Answer:</u> The given reaction is non-spontaneous in nature.

<u>Explanation:</u>

To calculate the $H^+$ concentration, we use the equation:

$pH=-\log[H^+]$

We are given:

pH of the solution = 7.5

$7.5=-\log [H^+]$

$[H^+]=10^{-7.5)=3.1\times 10^{-8}M$

For the given chemical equation:

$\text{Glyceraldehyde3-phosphate }+NAD^++HPO_4^{2-}\rightarrow \text{1,3-Biphosphoglycerate }+NADH+H^+$

The equation used to Gibbs free energy of the reaction follows:

$\Delta G=\Delta G^o+RT\ln K_{eq}$

where,

$\Delta G$ = free energy of the reaction

$\Delta G^o$ = standard Gibbs free energy = 6.3 kJ/mol = 6300 J/mol (Conversion factor: 1kJ = 1000J)

R = Gas constant = 8.314J/K mol

T = Temperature = $25^oC=[273+25]K=298K$

$K_{eq}$ = Ratio of concentration of products and reactants = $\frac{[BPG][NaDH][H^+]}{[G_3P][NAD^+][HPO_4^{2-}]}$

$[BPG]=3.0\times 10^{-3}M$

$[NADH]=1.0\times 10^{-4}M$

$[H^+]=3.1\times 10^{-8}M$

$[G_3P]=1.5\times 10^{-5}M$

$[NAD^+]=1.2\times 10^{-5}M$

$[HPO_4^{2-}]=1.2\times 10^{-5}M$

Putting values in above equation, we get:

$\Delta G=6300J/mol+(8.314J/K.mol\times 298K\times \ln (\frac{(3.0\times 10^{-3})\times (1.0\times 10^{-4})\times (3.1\times 10^{-8})}{(1.5\times 10^{-5})\times (1.2\times 10^{-5})\times (1.2\times 10^{-5})}))\\\\\Delta G=9917.02J/mol=9.92kJ/mol$

For the reaction to be spontaneous, the Gibbs free energy of the reaction must come out to be negative.

As, the Gibbs free energy of the reaction is positive. The reaction is said to be non-spontaneous.

Hence, the given reaction is non-spontaneous in nature.

4 0

2 years ago