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9966 [12]
3 years ago
11

A student placed 3.0 grams of Mg into some HCl in two different experiments. In each case, it reacted according to the following

equation:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g).

In the first experiment, it took 32 minutes for all of the Mg to react. In the second experiment, it took 54 minutes for all of the Mg to react. Which of the following could account for the change in reaction rate of the second experiment?



a catalyst was added



the Mg was powdered into H2



the H2 was decreased



the temperature was decreased
Chemistry
1 answer:
lana [24]3 years ago
6 0

Answer: -

A catalyst is a substance that speeds up the chemical reaction. In the first experiment it took 32 minutes for all the magnesium to react.

In the next it took 54 minutes for all the magnesium to react. So the reaction was slower the second time.

Thus a catalyst was not used.

Powdering up the Magnesium would mean increasing the surface area. More the surface area faster the reaction. Since the reaction is slowing down,

Magnesium was not powdered

If the temperature was decreased then kinetic energy would decrease of the reactant molecules and the reaction would slow down due to less number of collisions between reactant moleules.

So the temperature was decreased is a correct option.

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Magnesium has three naturally occurring isotopes with masses of 23.99, 24.99, and 25.98 amu and natural abundances of 78.99%, 10
Darya [45]
Atomic mass of magnesium = (23.99 x 78.99%) + (24.99 x 10.00%) + (25.98 x 11.01%)
= 24.31 g/mol
5 0
3 years ago
Where do you place the symbols that represent the state of matter in an equation?
nexus9112 [7]
Subscript in a pair of brackets
5 0
3 years ago
Convert 7.1x10^25 molecules of water to moles
ruslelena [56]

Answer:

<h2>117.94 moles</h2>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

n =  \frac{N}{L} \\

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

n =  \frac{7.1 \times  {10}^{25} }{6.02 \times  {10}^{23} }  \\  = 117.940199...

We have the final answer as

<h3>117.94 moles</h3>

Hope this helps you

8 0
2 years ago
Check the approach to obtain the correct conversion equation. Use the temperature in °F to find the temperature in °C.
Maru [420]

Answer:

( °F − 32) × 5/9 =  °C

Explanation:

Also there is a mental calculation to convert from Fahrenheit to Celsius. The ratio 5/9 is approximately equal 0.55555….

Subtract 32º to adapt the equivalent in the Fahrenheit scale.

Divide the degrees Celsius by 2 (multiply by 0.5).

Take 1/10 of this number (0.5 * 1/10 = 0.05) and add it to the number obtained previously.

Example: Convert 98.6º F to Centigrade.

98.6 - 32 = 66.6

66.6 * 1/2 = 33.3

33.3 * 1/10 = 3.3

33.3 + 3.3 = 36.6 which is an approximation in degrees Centigrade

8 0
3 years ago
Erythrogenic acid, C18H26O2, is an acetylenic fatty acid that turns avivid red on exposure to light. On catalytic hydrogenation
lara31 [8.8K]

Answer:

use research

Explanation:

6 0
2 years ago
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