A 5.0-gram sample of zinc and a 50.-milliliter sample of hydrochloric acid are used in a chemical reaction. Which combination of these samples has the fastest reaction rate?(1) a zinc strip and 1.0 M HCl(aq)
(2) a zinc strip and 3.0 M HCl(aq)
(3) zinc powder and 1.0 M HCl(aq)
(4) zinc powder and 3.0 M HCl(aq)

Answers

Answer 1
Answer:

Answer:

(4) zinc powder and 3.0 M HCl(aq)

Explanation:

First consider the equation of reaction:

Zn + 2HCl --> ZnCl_2 + H_2

1 mole of Zinc requires 2 moles of HCl for reaction.

mole of zinc = mass/molar mass = 5.0/65.38 = 0.0765 mole

0.0765 mole of zinc will require: 0.0765 x 2 = 0.1530 mole HCl

Mole of 1.0 M HCl = Molarity x volume = 1 x 0.05 = 0.05 mole

Mole of 3.0 M HCl = 3 x 0.05 = 0.15

Hence, the 3.0 M HCl is what will give the required number of mole.

Zinc in powder form will react faster compared to in strip because the former has higher surface area for reaction.

Therefore, zinc powder and 3.0 M HCl will give the fastest reaction rate.

The correct option is option 4.

Answer 2
Answer: The answer is Zine powder and 3.0 M HCl (aq)

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Does a solution have to involve a liquid? explain.

Answers

No, not always. There is always going to be solutions of gases in the air. And, there may be a solution of metals in alloys. 

Basically, a solution is just any of the same mixture, which is solid-solid, liquid-liquid, and gas-gas. 

Yes a solution does have to involve liquid. For example. when when dissolving a solid you must have liquid to do so. And it also must contain liquid for another liquid. The Fact f one substance dissolving into another substance will require liquid.

If gas particles start colliding with the walls of their metallic container with increase force what is their direct effect

Answers

Answer: The increase in force will directly effect the pressure exerted by the gas that is high pressure of the gas.

Explanation:

The pressure is defined as force applied per unit area.

Pressure=(Force)/(Area)

Pressure\propto Force

If the gas particles colliding with the walls of container with increase in force then the pressure of the gas exerted by the particles of the gas will also get increased.

I believe your answer would be higher gas pressure.

A closed system initially containing 1×10^-3M H2 and 2×10^-3 at 448°C is allowed to reach equilibrium. Analysis of the equilibrium mixture show s that the concentration of HI is 1.87×10^ -3. Calculate Kc at 448°C for the reaction.

Answers

Answer:

1.74845

Explanation:

We have the following reaction:

I2 + H2 => 2 HI

Now, the constant Kc, has the following formula:

Kc = [C] ^ c * [D] ^ d / [A] ^ a * [B] ^ b

In this case I2 is A, H2 is B and C is HI

We know that the values are:

 H2 = 1 × 10 ^ -3 at 448 ° C

I2 = 2 × 10 ^ -3 at 448 ° C

HI = 1.87 × 10 ^ -3 at 448 ° C

Replacing:

Kc = [1.87 × 10 ^ -3] ^ 2 / {[2 × 10 ^ -3] ^ 1 * [1 × 10 ^ -3] ^ 1}

Kc = 1.87 ^ 2/2 * 1

Kc = 1.74845

Which means that at 448 ° C, Kc is equal to 1.74845

Answer:

K_c = 51

Explanation:

[H2] = 10^-3

[I2] = 2*10^-3

[HI] = 0

in equilbiirum

[H2] = 10^-3 - x

[I2] = 2*10^-3 -x

[HI] = 0 + 2x

and we know

[HI] = 0 + 2x = 1.87*10^-3

x = ( 1.87*10^-3)/2 =  0.000935

then

[H2] = 10^-3 - 0.000935 = 0.000065

[I2] = 2*10^-3 -0.000935 = 0.001065

                        H₂                +          I              ⇄              2 HI

Initially     1 × 10⁻³                       2 × 10⁻³

Change  -9.35 × 10⁻⁴               -9.35 × 10⁻⁴                +1.87 × 10⁻³

At equil   6.5 × 10⁻⁵                  1.06 5 × 10⁻³               1.87 × 10⁻³

HI increase by 1.87 × 10⁻³M

K_c = ([HI]^2)/([H_2][I_2]) \n\n= ((1.87*10^-^3)^2)/((6.5*10^-^5)(1.065*10^-3)) \n\nK_c = 51

Which of these statements about enzymes is NOT true? - If enough substrate is added, the normal Vmax of a reaction can be attained even in the presence of a competitive inhibitor.
- When [S] << Km, the reaction is second order and V0 depends on [S] and [Et].
- Their kcat is a second order rate constant.
- The lower their Km, the better they recognize their substrate, but the lower their reaction rate.
- When [S] << Km, V0 depends on [S] and [Et].

Answers

Answer:

1. True. 2. True. 3. Not true. 4. True. 5. True

Explanation:

1. Yes, because if the amount of substrate i much greater than of competitive inhibitor then the probability of substrate to bind to ferment is much higher than of inhibitor (if we have noncompetitive inhibitor it damages the structure of active site and the substrate concentration does not have a role in reaction rate).

2. Yeah, because then the michaelis-menten equation will transform into [tex} V0=(kcat*[E]*[S])/Km [/tex] and it is a second order equation.

3. No, because it is measured in sec-1 and that means it is 1 rate constant.

4. True, if the lower Km the better is binding and due to that rate is slower because it's harder for substrate to unbind.

5. The same as question two.

4. HOW MANY MOLECULES ARE IN 1.5 MOL OF SULFUR TRIOXIDE?

Answers

Sulfur trioxide is SO3
Now to find number of particles we take number of moles x avogadros number.
1.5 x (6.02x10^23) = 9.03x10^23 molecules

Which of these is a physical property?A) ability to burn a piece of paper

B) pure sodium reacts violently with water

C) the boiling point of water is 100’C

D) helium does not tend to react with anything

Answers

Hey

I think the answer is c) the boiling point of water is 100’c

I hope this helped xxx