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3 years ago

What are three ways that we can identify when a chemical reaction is occurring?

Chemistry

1 answer:

Nina [5.8K]3 years ago

6 0

Three ways (out of the many) are:

Change of temperature
Color change
Formation of gas

Hope this helps!! (:

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Which of the following contains a polar covalent bond?

a_sh-v [17]

Hi the answer is C. I believe.

7 0

3 years ago

Determine the hydronium ion concentration in a solution that is 0.0005 m hcl. answer in units of m.

erma4kov [3.2K]

H₃O ions are when water is protonated
H₂O + H⁺ --> H₃O⁺
HCl is a strong acid therefore complete ionisation takes place.
HCl ---> H⁺ + Cl⁻
1 mol of HCl dissociates to give out 1 mol of H⁺
since H⁺ together with water forms H₃O⁺ ions,
[HCl] = [H₃O⁺]
therefore concentration of [H₃O⁺] is 0.0005 M

5 0

3 years ago

Is sugar a homogeneous mixture?

Vinvika [58]

Yes

hope this really helps

3 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 p<em>Kₐ</em>:

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

In conclusion, the p<em>Kₐ </em>value of lactic acid is about 3.856.

5 0

2 years ago

Which of the following conditions would lead to a small population size? a. a low birth to death ratio b. a high birth to death

Vinil7 [7]

Answer:

Choice A.

A low birth to death ratio

Explanation:

A low birth to death ratio means that people are dying faster than they are being born. This leads to a decreasing population size.

4 0

2 years ago