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3 years ago

Why take the initial and final temperature?

1 answer:

3 0

If you are doing an experiment with chemicals, you would like to take the initial temperature, then do the experiment. After you do the experiments, you would like to take the temperature again to see if the chemicals made the temperature increase or decrease.

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Which statement explains the energy term in this reaction

lana66690 [7]

Answer:

Mass is lost due to the conversion of mass to energy

Explanation:

The question is not complete, the complete question is given as:

$^{235}_{72}U +^{1}_{0}n$ ⇒ $^{140}_{56}Ba+^{93}_{36}Kr+3^{1}_{0}n+energy$

total mass equals 236.053 u total mass equals 235.868 u

Which statement explains the energy term in this reaction? (1) Mass is gained due to the conversion of mass to energy. (2) Mass is gained due to the conversion of energy to mass. (3) Mass is lost due to the conversion of mass to energy. (4) Mass is lost due to the conversion of energy to mass.

Answer: From Einstein’s equation E = mc², when a radioisotope element undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass.This mass lost is converted to energy.

The law of conservation of energy holds for this type of reaction (i.e the sum of mass and energy is remains the same in a nuclear reaction). Mass changes to energy, but the total amount of mass and energy combined remains the same before and after a nuclear reaction.

From the reaction above, the total decrease in mass = 236.053 - 235.868 = 0.185 u

4 0

3 years ago

enzyme‑catalyzed, single‑substrate reaction E + S − ⇀ ↽ − ES ⟶ E + P . The model can be more readily understood when comparing t

laila [671]

Complete Question

The complete question is shown on the first uploaded image

Answer:

[S]<<KM | [S]=KM | [S]>>KM | Not true

____________ | Half of the active | Reaction rate is | Increasing

$[E_{free}]$ is about | sites are filled of | independent of | $[E_{Total}]$ will

equal to $[E_{total}]$ . | | [S] | lower KM

_____________________________________________|____________

[ES] is much | | Almost all active

lower than | | sites are filled

$[E_{free}]$ | |

Explanation:

Generally the combined enzyme $[ES]$ is mathematically represented as

$[ES] = \frac{[E_{total}][S]}{K_M + [S]}----(1)$

for Michaelis-Menten equation

Where $[S]$ is the substrate concentration and $K_M$ is the Michaelis constant

Considering the statement $[S] < < K_M$

Looking at the equation $[S]$ is denominator so it can be ignored(it is far too small compared to $K_M$ ) hence the above equation becomes

$[ES] = \frac{[E_{total}][S]}{K_M}$

Since $[S]$ is less than $K_M$ it means that $\frac{[S]}{K_M} < < 1$

so it means that $[ES] < < [E_{total}]$

What this means is that the number of combined enzymes $[ES]$ i.e the number of occupied site is very small compared to the the total sites $[E_{total}]$ i.e the total enzymes concentration which means that the free sites [ $E_{free}]$ i.e the concentration of free enzymes is almost equal to $[E_{total}]$

Considering the second statement

$[S] = K_M$

So this means that equation one would now become

$[ES] = \frac{[E_{total}][S]}{2[S]} = \frac{[E_{total}]}{2}$

So this means that half of the active sites that is the total enzyme concentration are filled with S

Considering the Third Statement

$[S] >>K_M$

In this case the $K_M$ in the denominator of equation 1 would be neglected and the equation becomes

$[ES] = \frac{[E_{total}] [S]}{[S]} = [E_{total}]$

This means that almost all the sites are occupied with substrate

The rate of this reaction is mathematically defined as

$v =\frac{V_{max}[S]}{K_M [S]}$

Where v is the rate of the reaction(also know as the velocity of the reaction at a given time t) and $V_{max}$ is he maximum velocity of the reaction

In this case also the $K_M$ at the denominator would be neglected as a result of the statement hence the equation becomes

$v = \frac{V_{max}[S]}{[S]} = V_{max}$

So it means that the reaction does not depend on the concentration of substrate [S]

For the final statement(Not True ) it would match with condition that states that increasing $[E_{total}]$ will lower $K_M$

This is because $K_M$ does not depend on enzyme concentration it is a property of a enzyme

7 0

3 years ago

Match the following reactions with the reaction type. You may use each type more than once.

vaieri [72.5K]

Answer:

1) Decomposition

2)Double-replacement reaction

3)synthesis

4)Double-replacement reaction

5)single-replacement reaction

6)Double-replacement reaction

Explanation:

Step 1: Data given

Synthesis: This is a reaction where two or more reactants will combine to form a new, single product. This is occurs when two or more reactants combine to form a single product. This can be shown with the following equation.

A + B → C

A and B are the reactants to form a new product C

Decomposition: This is a reaction where 1 (more complex) compound will be broken down into 2 or more (more simple) products.

This can be shown by the following equation:

AB → A + B

A single replacement: This is a reaction where one element wil be replaced by another element in the same compound. This can be shown by the following equation:

A + BC → B + AC

Here is the elemnt B in the compound BC, replaced by the element A, to form a new compound AC

A double-replacement: This is a reaction where the positive and negative ions of two ionic compounds will be exchanged and 2 new compounds willbe formed. This can be shown by the following equation:

AB+CD→AD+BC

A combustion reaction requires oxygen gas (O2) to produce the products CO2 and H2O

Step 2:

1) 2HgO(s) → 2Hg(l) + O2(g)

⇒ Decomposition

2) KCl(aq) + AgNO3(aq) → AgCl(s) + KNO3(aq)

⇒ Double-replacement reaction

3) 2Na(s) + H2(g) → 2NaH(s)

⇒ synthesis

4) Mg(OH)2(aq) + 2HNO2(aq) → Mg(NO2)2(aq) + 2 H2O(l)

⇒ Double-replacement reaction

5) Ca(s) + 2AgNO3(aq) → Ca(NO3)2(aq) + Ag(s)

⇒ Single-replacement reaction

6) Al2O3(s) + H2SO4(aq) → Al2(SO4)3(aq) + H2O(l)

⇒ Double-replacement reaction

8 0

3 years ago

I need help with #10 (a,b and c) please and thank you!

Sidana [21]

a. An oxidation reaction. An oxidation reaction is a type of chemical reaction that involves a transfer of electrons between two species.

6 0

3 years ago

Please select the best answer and click "submit."

vladimir1956 [14]

When it comes to physical changes like phase changes, there are two types of heat energy: sensible heat and latent heat. Sensible heat is the heat absorbed/released when you heat the substance but it doesn't change phase. An example would be heating lukewarm water. The substance is liquid all throughout. Latent heat, on the other hand, is the heat absorbed/released when there is a phase change. An example would be boiling water, because it changes liquid to vapor.

Hence, for freezing liquid, you use the latent heat, specifically the heat of fusion. The answer should be

2.5 g * (1 mol/18.02 g) * 6.03 kJ/mol = 0.84 kJ/mol

The answer is not in the choices. You only use Hvap if you boil water.

5 0

3 years ago