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4 years ago

#1: Which of the following statements is true?

2 answers:

6 0

Endothermic reactions take in heat from the environment in order to react while exothermic reactions release heat during the reaction. For this, D must be true as the products have less energy because they have released heat during the reaction. A and C are incorrect because they products and reactants are equal and B is wrong because the energy of the products would be more as the reaction took in heat.

wlad13 [49]4 years ago

4 0

Answer: Option (D) is the correct answer.

Explanation:

In an endothermic reaction energy is absorbed by reactant molecules in a chemical reaction as a result energy of products is more than the energy of reactants.

Whereas in an exothermic reaction energy is released by a chemical reaction as a result energy of reactants is more than the energy of products.

Therefore, we can conclude that the correct statement is in an exothermic reaction, the energy of the products is less than the energy of the reactants.

You might be interested in

The rate constant for a certain reaction is k = 4.50×10−3 s−1 . If the initial reactant concentration was 0.400 M, what will the

SIZIF [17.4K]

Answer: The concentration of reactant after the given time is 0.0205 M

Explanation:

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $4.50\times 10^{-3}s^{-1}$

t = time taken for decay process = 11.0 min = 660 s (Conversion factor: 1 min = 60 s)

$[A_o]$ = initial amount of the reactant = 0.400 M

[A] = amount left after decay process = ?

Putting values in above equation, we get:

$4.50\times 10^{-3}s^{-1}=\frac{2.303}{660s}\log\frac{0.400}{[A]}$

$[A]=0.0205M$

Hence, the concentration of reactant after the given time is 0.0205 M

4 0

3 years ago

HELP ME please i need help with this

nadezda [96]

4)
a) Natural selection will work negatively against rabbits that only eat berries as the drought is preventing berries from growing. It wont have any negative impact on rabbits that only eat grass as the grass is still surviving.

b) The statement ‘population has variations’ is backed up by the fact that the rabbits eat different things. They aren’t all the same. The statement ‘some variations are favorable’ is backed up by the fact that the rabbits that only eat grass are able to survive the drought. Their variation in eating grass instead of berries let’s them live. The statement ‘a population will change over time’ is backed up by the fact that the rabbits that only eat berries will die out. This will not only change the size of the population but going forward will create a population that has more rabbits that eat only grass on account of natural selection.

7 0

3 years ago

what happens to the rf value of your compound if you change your solvent from methylene chloride to methanol?

Masja [62]

Rf values may vary. Rf values vary depending on the material and solvent. The solvent that is used will alter the Rf value.

Rf values are typically higher for low polarity chemicals compared to higher polarity ones. Generally speaking, as polarity of a compound increases, so does its adsorptivity (i.e. the more polar the compound then the stronger it binds to the adsorbent). Solvents get more eluting as they become more polar.

The greater the compound's polarity, the more readily it will bind to the adsorbent, the closer it will come to the baseline, and the lower its Rf value. Many scientists use normal-phase flash chromatography with dichloromethane and methanol as the mobile phase to purify polar organic molecules. Due to methanol's high polarity and protic chemistry, it can frequently be difficult to optimize this solvent system.

Learn more about to visit here:

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6 0

1 year ago

How many miles of carbon are needed to react with 5.44moles of so2

Romashka-Z-Leto [24]

The answer is 13.6 moles c

3 0

4 years ago

Neptune is 30 AU (astronomical units) from the sun. How long, in light minutes, would it take for light from the sun to reach Ne

shtirl [24]

Answer:

250 light minutes takes

Explanation:

1 astonomical unit is equal to 1.50x10¹¹m

The light travels at the speed of 3.0x10⁸m/s. That means in 1 second, travels 3.0x10⁸m. To solve this question we must find the distance of neptune to the sun in meters. In this way we can find the seconds (And minutes) that need the light to travel from the sun to neptune:

Distance from Sun to neptune:

30AU * (1.50x10¹¹m / 1AU) = 4.5x10¹²m

Time transcurred:

4.5x10¹²m * (1s / 3.0x10⁸m) = 15000s

15000s * (1min / 60s) =

<h3>250 light minutes takes</h3>

7 0

3 years ago