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2 years ago

Pls help!!!!!

Chemistry

2 answers:

umka2103 [35]2 years ago

7 0

The exact positions of the electrons in an atom cannot be determined because electrons are always .

erica [24]2 years ago

3 0

Answer:

moving i think! Hope this helps

Explanation:

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When the temperature of a reacting mixture increases, the rate of reaction increases. Which statement explains why the rate of r

wlad13 [49]

Answer:

This is one of the factors that affects chemical reactions

Temperature:This is because when the temperature is raised energy in form of heat is supplied to the reacting particles and so the rate of reaction is increased.

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3 years ago

Which of the following characteristics helps to distinguish a biome?

ladessa [460]

Answer: a biome is defined by its biogeography, temperature, and precipitation

Explanation:

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3 years ago

For which of the following equilibria does `"K"_("eq") = ["O"_2]`? A. O2(l) O2(g) B. 2O3(g) 3O2(g) C. 2H2O(l) 2H2(g) + O2(g) D.

Feliz [49]

For plato users

the answer is a. O2(l) O2(g)

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8 0

2 years ago

Read 2 more answers

The na+/k+ pump removes ______ na+ ions and adds _______ k+ ions.

Paladinen [302]

Sodium potassium pump is an active pump which transfer sodium and potassium ions across the membrane with the expenditure of energy in the form of ATP.

This kind of pump is generally used in nerve cells.

The pump works against the concentration gradient as the pump moves three Na+ ions outside the cell and two K+ ions inside the cell, though there is a high concentration of Na+ outside the cell and a low concentration of K+ outside the cell.

3 0

2 years ago

An unknown compound, X is thought to have a carboxyl group with a pKa of 2.0 and another ionizable group with a pKa between 5 an

Westkost [7]

Answer:

7.3

Explanation:

By Henderson Hasselbalch equation we can calculate the pH or the pOH of a solution by its pKa. Remember that $pH = -log[H^{+}]$ , and pKa = -logKa. Ka is the equilibrium constant of the acid.

Henderson Hasselbalch equation :

$pH = pKa - log \frac{[HA]}{[A^{-}]}$

Where [HA] is the concentration of the acid, and $[A^{-}]$ is the concentration of the anion which forms the acid.

So, acid X, has two ionic forms, the carboxyl group and the other one. First, we have 0.1 mol/L of the acid, in 100 mL, so the number of moles of X

n1 = (0.1 mol/L)x(0.1 L) = 0.01 mol

When it dissociates, it forms 0.005 mol of the carboxyl group and 0.005 mol of the other group. Assuming same stoichiometry.

Adding NaOH, with 0.1 mol/L and 75 mL, the number of moles of $OH^-$ will be

n2 = (0.1 mol/L)x(0.075 L) = 0.0075 mol

So, the 0.0075 mol of $OH^-$ reacts with 0.005 mol of carboxyl, remaining 0.0025 mol of $OH^-$ , which will react with the 0.005 mol of the other group. So, it will remain 0.0025 mol of the other group.

The final volume of the solution will be 175 mL, but both concentrations (the acid form and ionic form) have the same volume, so we can use the number of mol in the equation.

Note that, the number of moles of the acid form is still 0.01 mol because it doesn't react!

So,

$6.72 = pKa - log \frac{0.01}{0.0025}$

6.72 = pKa - log 4

pKa - log4 = 6.72

pKa = 6.72 + log4

pKa = 6.72 + 0.6

pKa = 7.3

8 0

3 years ago