All categories

3 years ago

I’m sorry I’m confused can you help me?

Chemistry

1 answer:

Amanda [17]3 years ago

5 0

Answer:

2 electrons

Explanation:

The first principal energy level contains only an s sublevel; therefore, it can hold a maximum of two electrons.

You might be interested in

You need to produce a buffer solution that has a pH of 5.31. You already have a solution that contains 10. mmol (millimoles) of

Karolina [17]

Answer:

37 mmol of acetate need to add to this solution.

Explanation:

Acetic acid is an weak acid. According to Henderson-Hasselbalch equation for a buffer consist of weak acid (acetic acid) and its conjugate base (acetate)-

$pH=pK_{a}(acetic acid)+log[\frac{mmol of CH_{3}COO^{-}}{mmol of CH_{3}COOH }]$

Here pH is 5.31, $pK_{a}$ (acetic acid) is 4.74 and number of mmol of acetic acid is 10 mmol.

Plug in all the values in the above equation:

$5.31=4.74+log[\frac{mmol of CH_{3}COO^{-}}{10}]$

or, mmol of $CH_{3}COO^{-}$ = 37

So 37 mmol of acetate need to add to this solution.

3 0

3 years ago

5. A box with a volume of 22.4 L contains 1.0 mol of nitrogen and 2.0 mol of hydrogen at 0°C. Which of the following statements

love history [14]

B. The partial pressure of N2 is 101 kPa

<h3>Further explanation</h3>

Given

volume = 22.4 L

1.0 mol of nitrogen and 2.0 mol of hydrogen at 0°C

Required

Total pressure and partial pressure

Solution

Ideal gas law :

PV = nRT

n total = 3 mol

T = O °C + 273 = 273 K

P = nRT/V

P = 3 x 0.08205 x 273 / 22.4

P total = 3 atm = 303,975 kPa

P Nitrogen = 1/3 x 303.975 = 101.325 kPa

P Hydrogen = 2/3 x 303.975 = 202.65 kPa

7 0

3 years ago

Classify the following reactions: HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l) Ba(OH)2(aq)+ZnCl2(aq)→BaCl2(a

Savatey [412]

The reactions are

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

Ba(OH)2(aq) + ZnCl2(aq) → BaCl2(aq) + Zn(OH)2(s)

2AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2Ag(s)

Answer:

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) = Acid-base reaction

Ba(OH)2(aq) + ZnCl2(aq) → BaCl2(aq) + Zn(OH)2(s) = Precipitation reaction

2AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2Ag(s) = Redox reaction

Explanation:

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) .

The reaction above is an example of an acid-base reaction. Acid-base reaction is a chemical reaction between an acid and a base. The product is usually a salt and water. An acid dissolves in water to produce H+ ion. Hydrochloric acid is a strong acid as it is completely dissociated in water. A base dissolves in water to form hydroxide ion(OH-). The sodium hydroxide is a strong base as it completely dissociate in water. The reaction between a base and an acid can be known as a neutralization reaction.

Ba(OH)2(aq) + ZnCl2(aq) → BaCl2(aq) + Zn(OH)2(s)

The reaction above is a precipitation reaction. Precipitation reaction is a reaction where two ionic bonds or cations and anions in an aqueous solution react to form an insoluble salts. The insoluble salt formed is known as the precipitate. The reaction above is an example of a double replacement reaction. From the equation the ions replace each other depending on the cations and anions. They switch partners as both reactants lose their partners to form new partnership with a different ion. The two reactants ( Ba(OH)2 and ZnCl2 ) are aqueous solution, they react to from a solid precipitates( Zn(OH)2(s) ).

2AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2Ag(s)

The reaction is known as an oxidation-reduction reaction(Redox reaction). A oxidation-reduction reaction their is a transfer of electron(s) between two species. The oxidation number of a chemical reaction changes by losing or gaining electrons. One of the reactant is a reducing agent and the other is an oxidizing agent.

From the reaction Mg is the reducing agent and AgNO3 is the oxidizing agents.

2 Ag+ + 2 e- → 2 Ag∧0 (reduction)

Mg∧0 - 2 e- → Mg²+ (oxidation)

8 0

3 years ago

The temperature of a 95.4 g piece of Cu increases from 25.0 °C to 48.0 °C when the Cu absorbs 849 J of heat. What is the specifc

melisa1 [442]

<h3>Answer:</h3>

0.387 J/g°C

<h3>Explanation:</h3>

To calculate the amount of heat absorbed or released by a substance we need to know its mass, change in temperature and its specific heat capacity.
Then to get quantity of heat absorbed or lost we multiply mass by specific heat capacity and change in temperature.
That is, Q = mcΔT

in our question we are given;

Mass of copper, m as 95.4 g

Initial temperature = 25 °C

Final temperature = 48 °C

Thus, change in temperature, ΔT = 23°C

Quantity of heat absorbed, Q as 849 J

We are required to calculate the specific heat capacity of copper

Rearranging the formula we get

c = Q ÷ mΔT

Therefore,

Specific heat capacity, c = 849 J ÷ (95.4 g × 23°C)

= 0.3869 J/g°C

= 0.387 J/g°C

Therefore, the specific heat capacity of copper is 0.387 J/g°C

3 0

3 years ago

Hey I'm a newbie any help please with this

solniwko [45]

6 A
7 A
8 B
9 B
10 A
11 C

4 0

3 years ago