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Lostsunrise [7]
2 years ago
15

A chemist needs 0.550 mol selenium for a reaction. What mass of selenium should a chemist use?

Chemistry
1 answer:
-BARSIC- [3]2 years ago
4 0

Answer:

The chemist would require to use 43.43 grams.

Explanation:

In order to solve this problem we need to know<u> how much do 0.550 moles of selenium weigh</u>. To do that we use selenium's<em> molar mass </em>and multiply it by the given number of moles:

  • 0.550 mol * 78.96 g/mol = 43.43 g

The chemist would require to use 43.43 grams.

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Chapter 15 of your textbook discusses conjugation and various reactions of 1,3-dienes. In CHE 321, we discussed various ways to
xxMikexx [17]

Answer:

Dienes are alkenes that contain two carbon-carbon double bonds, so they have the same properties as these hydrocarbons.

In the attached file are the two reactions of dienes production.

Explanation:

Two ways to obtain dienes are as follows:

-Reaction of oxidative dehydrogenation of an alkane, is an exothermic process and occurs at lower temperatures, diene and water are formed, generating greater conversion at lower temperature levels.

-Dehydration of primary alcohols. The treatment of alcohols with acid at elevated temperatures produces dienes due to water loss. For example, heating ethanol in the presence of sulfuric acid produces ethene by the loss of a water molecule.

Download pdf
5 0
3 years ago
The progress of the reaction:
Blababa [14]

Answer:

The Equilibrium constant K is far greater than 1; K>>1

Explanation:

The equilibrium constant, K, for any given reaction at equilibrium, is defined as the ratio of the concentration of the products raised to their stoichiometric coefficients divided by the concentration of reactants raised to their stoichiometric coefficients.

It tells us more about how how bigger or smaller the concentration of products is to that of the reactants when a reaction attains equilibrium. From the given data, as the color of the reactant mixture (Br2 is reddish-brown, and H2 is colourless) fades, more of the colorless product (HBr is colorless) is being formed as the reaction approaches equilibrium. This indicates yhat the concentration of products becomes relatively higher than that of the reactants as the reaction progresses towards equilibrium, the equilibrium constant K, must be greater than 1 therefore.

6 0
3 years ago
Acetone is one of the most important solvents in organic chemistry. It is used to dissolve everything from fats and waxes to air
Yanka [14]

Answer: a. 79.6 s

b. 44.3 s

c. 191 s

Explanation:

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

t_{\frac{1}{2}}=\frac{0.693}{8.7\times 10^{-3}s^{-1}}=79.6s

b) for completion of 32% of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-32}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{68}

t=44.3s

c) for completion of 81 % of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-81}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{19}

t=191s

4 0
2 years ago
What sequence of enzymes allows for the synthesis of glycogen from glucose-6-phosphate?
Nutka1998 [239]

Answer:

The answer is (e) : phosphoglucomutase, UDP-glucose pyrophosphorylase, glycogen synthase then amylo-(1,4-1,6)-transglycosylase.

Explanation:

Phosphoglucomutase: Convert glucose-6-phosphate to glucose-1-phosphate.

UDP-glucose pyrophosphorylase:  Form UDP-glucose from glucose-1-phosphate.

Glycogen synthase: Add the new glucose from UDP-glucose to the growing glycogen chain.

Amylo-(1,4-1,6)-transglycosylase: This is a branching enzyme, it initiates formation of branches evolving from the main chain.

4 0
2 years ago
385 J of heat are needed to heat a piece of aluminum from 22°C to 45°C. If the specific heat of Al is 0.90 J/g°C, what is the ma
VikaD [51]

Answer:

M of Al=33.09g or 0.0331kg

Explanation:

Heat Energy= specific heat*mass*change in temperature

H=M*C*T

make M subject of the formula

M=H/CT

M=685J/0.90J/g°C*(45°C-22°C)

M=685J/0.90J/g°C*23°C

M=685J/20.7J/g

M=33.09g or 0.0331kg

4 0
3 years ago
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