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3 years ago

Which element has the same number of energy levels as aluminum (Al) and the same number of valence electrons as calcium (Ca)?

Chemistry

2 answers:

Zigmanuir [339]3 years ago

6 0

The correct answer is Magnesium (Mg)

scZoUnD [109]3 years ago

5 0

Answer:

magnesium

Explanation:

because i just did the test and ik this is the answer

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A gas is at a pressure of 3.70 atm. What is this pressure in kilopascals?

Yanka [14]

Answer:
= 374.90 kPa

Calculation:
As we know atm and kiloPascal are related to each other as,

1 atm = 101.325 kPa
So,
3.70 atm = X
Solving for X,
X = (3.70 atm × 101.325 kPa) ÷ 1 atm

X = 374.90 kPa

7 0

3 years ago

Calculate the pKa of lactic acid (CH3CH(OH)COOH) given the following information. 3.005 grams of potassium lactate are added to

snow_lady [41]

Answer:

$\displaystyle \text{p} K_a \approx 3.856$

Explanation:

Because 3.005 grams of potassium lactate is added to 100. mL of solution, its concentration is:

$\displaystyle \begin{aligned} \left[ \text{KC$_3$H_$_5$O$_3$}\right] & = \frac{3.005\text{ g KC$_3$H_$_5$O$_3$}}{100.\text{ mL}} \cdot \frac{1\text{ mol KC$_3$H_$_5$O$_3$}}{128.17 \text{ g KC$_3$H_$_5$O$_3$}} \cdot \frac{1000\text{ mL}}{1\text{ L}} \\ \\ &= 0.234\text{ M}\end{aligned}$

By solubility rules, potassium is completely soluble, so the compound will dissociate completely into potassium and lactate ions. Therefore, [KC₃H₅O₃] = [C₃H₅O₃⁺]. Note that lactate is the conjugate base of lactic acid.

Recall the Henderson-Hasselbalch equation:

$\displaystyle \begin{aligned}\text{pH} = \text{p}K_a + \log \frac{\left[\text{Base}\right]}{\left[\text{Acid}\right]} \end{aligned}$

[Base] = 0.234 M and [Acid] = 0.500 M. We are given that the resulting pH is 3.526. Substitute and solve for pKₐ:

$\displaystyle \begin{aligned} (3.526) & = \text{p}K_a + \log \frac{(0.234)}{(0.500)} \\ \\ 3.526 & = \text{p}K_a + (-0.330) \\ \\ \text{p}K_a & = 3.856\end{aligned}$

In conclusion, the pKₐ value of lactic acid is about 3.856.

5 0

1 year ago

HELP PLEASE!!!!!

Mashutka [201]

Answer:

National fire protection Association

Explanation:

the nfpa is a global self funded nonprofit orgnazation establised in 1896 devoted to eliminating death injury protery loss and ecomomic loss due to fire and electrical hazards

4 0

3 years ago

How many electrons in mole will discharge 2g of Copper 2 ions

Karo-lina-s [1.5K]

Explanation:

96.485 columbs=1 faraday will

deposit 64/2g= 32 g cu ion

therfore it will require

96,485 ×2/32 =? coulombs or 1/16 of

Faraday= 1 / 16 mole of electrons .

7 0

3 years ago

How many atoms of each element are in the chemical formula P2O5?

marshall27 [118]

Answer:A

Explanation:2 phosphorus and 2 oxygen

4 0

3 years ago