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Likurg_2 [28]
2 years ago
15

Which statement is correct?

Chemistry
1 answer:
rosijanka [135]2 years ago
4 0

Answer:

B. Chemical changes produce new substances; physical changes do not.

Explanation:

Physical changes only alter appearances, while chemical changes are interactions that create new chemical formulas.

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Which of the following statements describes a common characteristic of catabolic pathways?
Anna71 [15]

Answer:

C. They are exergonic and provide energy that can be used to produce ATP form ADP and Pi.

Explanation:

There are 2 types of metabolic reactions.

  1. Anabolic reactions (Anabolism)
  2. Catabolic reactions (Catabolism)

CATABOLIC REACTIONS:

They consist of reactions in which larger molecules are broken down into simpler ones. They are exergonic i.e. energy producing reactions. The released energy can be stored in the form of ATP (energy currency of cell).

ANABOLIC REACTIONS:

They consist of reactions in which larger molecules are synthesized from simpler ones. They are endergonic reactions i.e. energy is absorbed.

MEMORY AID:

An easy way to remember catabolic reactions is to think of them as "catastrophic reactions" i.e. larger molecules are destructed to produce simpler ones.

Coming back to the question,

<u>a. They require energy from ATP hydrolysis to break down polymers into monomers. </u>

Energy requiring reactions are anabolic and so this is the incorrect answer.

<u>b. They are endergonic and release energy that can be used for cellular work.</u>

Endergonic reactions are anabolic and hence this is the incorrect answer.

<u>c. They are exergonic and provide energy that can be used to produce ATP from ADP and Pi</u>

This statement correctly fits the definition of Catabolic reactions and is therefore the correct answer.

<u>d. They combine small molecules into larger, more energy-rich molecules.</u>

This statement describes anabolic reactions and hence the incorrect choice.

3 0
3 years ago
Which salt shows the least solubility change when the temperature is increased from 0 to 100 c?
Hunter-Best [27]
Sodium chloride (NaCl), whose only changes about 5g/100mL water over that entire range 100°C)
4 0
3 years ago
Read 2 more answers
A rigid tank contains 0.66 mol of oxygen (O2). Find the mass of oxygen that must be withdrawn from the tank to lower the pressur
dsp73

Answer:

12.8 g of O_{2} must be withdrawn from tank

Explanation:

Let's assume O_{2} gas inside tank behaves ideally.

According to ideal gas equation- PV=nRT

where P is pressure of O_{2}, V is volume of O_{2}, n is number of moles of O_{2}, R is gas constant and T is temperature in kelvin scale.

We can also write, \frac{V}{RT}=\frac{n}{P}

Here V, T and R are constants.

So, \frac{n}{P} ratio will also be constant before and after removal of O_{2} from tank

Hence, \frac{n_{before}}{P_{before}}=\frac{n_{after}}{P_{after}}

Here, \frac{n_{before}}{P_{before}}=\frac{0.66mol}{43atm} and P_{after}=17atm

So, n_{after}=\frac{n_{before}}{P_{before}}\times P_{after}=\frac{0.66mol}{43atm}\times 17atm=0.26mol

So, moles of O_{2} must be withdrawn = (0.66 - 0.26) mol = 0.40 mol

Molar mass of O_{2} = 32 g/mol

So, mass of O_{2} must be withdrawn = (32\times 0.40)g=12.8g

7 0
3 years ago
How many valance electrons does group #11 have?
galina1969 [7]

It would have 11 valance electrons.

Example/Explanation:

Say we are talking about groups 10. Group 10 would have 10 valance electrons because of the atom's electronic arrangement in the periodic table.

6 0
3 years ago
Some antacid tables contain aluminum hydroxide. The aluminum hydroxide reacts with stomach acid according to the equation: Al(OH
MatroZZZ [7]

Answer:

26.67 mol HCl

Explanation:

Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O

In order to solve this problem, we need to c<u>onvert Al(OH)₃ moles to HCl moles</u>.

To do so we use the<em> stoichiometric ratios</em> of the balanced reaction:

  • 8.89 mol Al(OH)₃ * \frac{3molHCl}{1molAl(OH)_{3}} = 26.67 mol HCl

Thus 26.67 moles of HCl would react completely with 8.89 moles of Al(OH)₃.

4 0
3 years ago
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