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3 years ago

The element X has 2 valence electrons. its is a

Chemistry

1 answer:

Lesechka [4]3 years ago

6 0

helium, beryllium, magnesium, calcium, strontium, barium, radium. i believe any of these are proper answers.

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How do I find the number of moles and molar mass of Gas A and Gas B with the information provided?

drek231 [11]

Answer:

Explanation:

hope this helped sorry if its wrong!

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2 years ago

Diatoms are made of _____, which is used for industrial processes. calcium chitin silica cellulose

Alla [95]

A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica (hydrated silicon dioxide) called a frustule.

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2 years ago

Read 2 more answers

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

What volume does 0.482 mol of gas occupy at a pressure of 719 mmHg at 56 ∘C?

kozerog [31]

Answer:

The volume is 13, 69 L

Explanation:

We use the formula PV=nRT. We convert the temperature in Celsius into Kelvin and the pressure in mmHg into atm.

0°C= 273K---> 56°C= 56 + 273= 329K

760 mmHg----1 atm

719 mmHg----x= (719 mmHgx 1 atm)/760 mmHg= 0,95 atm

PV=nRT ---> V= (nRT)/P

V=( 0,482 molx 0,082 l atm/K mol x 329K)/0,95 atm

V=13,68778526 L

7 0

3 years ago

Finding the pH for [H+] = 9.4 * 10-3 M?

saul85 [17]

Answer:

pH = 2.0

Explanation:

To find the pH of a solution, take the -log[H+]. In this case, the -log(9.4 x 10^-3) equals 2.02687 which makes 2.0 when accounting for significant figures.

3 0

2 years ago