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Lubov Fominskaja [6]
3 years ago
7

A student walks 2km in 30 minutes. What is the student's average speed in km/h

Chemistry
1 answer:
crimeas [40]3 years ago
4 0

Answer:

4km per hour

Explanation:

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Why is an excited atom more reactive than a neutral?
tester [92]
The excited atom is positive when then neutral has no charge

7 0
3 years ago
11) Which group of Elements have Similar chemical Properties? *
Kryger [21]
Ca, Sr, Ba have similar chemical properties.
Explanation: They are in the same group (Alkaline Earth Metals)
6 0
3 years ago
PbSO4 has a Ksp = 1.3 * 10-8 (mol/L)2.
Oduvanchick [21]

i. The dissolution of PbSO₄ in water entails its ionizing into its constituent ions:

\mathrm{PbSO_{4}}(aq) \rightleftharpoons \mathrm{Pb^{2+}}(aq)+\mathrm{SO_4^{2-}}(aq).

---

ii. Given the dissolution of some substance

xA{(s)} \rightleftharpoons yB{(aq)} + zC{(aq)},

the Ksp, or the solubility product constant, of the preceding equation takes the general form

K_{sp} = [B]^y [C]^z.

The concentrations of pure solids (like substance A) and liquids are excluded from the equilibrium expression.

So, given our dissociation equation in question i., our Ksp expression would be written as:

K_{sp} = \mathrm{[Pb^{2+}] [SO_4^{2-}]}.

---

iii. Presumably, what we're being asked for here is the <em>molar </em>solubility of PbSO4 (at the standard 25 °C, as Ksp is temperature dependent). We have all the information needed to calculate the molar solubility. Since the Ksp tells us the ratio of equilibrium concentrations of PbSO4 in solution, we can consider either [Pb2+] or [SO4^2-] as equivalent to our molar solubility (since the concentration of either ion is the extent to which solid PbSO4 will dissociate or dissolve in water).

We know that Ksp = [Pb2+][SO4^2-], and we are given the value of the Ksp of for PbSO4 as 1.3 × 10⁻⁸. Since the molar ratio between the two ions are the same, we can use an equivalent variable to represent both:

1.3 \times 10^{-8} = s \times s = s^2 \\s = \sqrt{1.3 \times 10^{-8}} = 1.14 \times 10^{-4} \text{ mol/L}.

So, the molar solubility of PbSO4 is 1.1 × 10⁻⁴ mol/L. The answer is given to two significant figures since the Ksp is given to two significant figures.

8 0
3 years ago
Which effect can you observe when the starting K2Cr2O7is diluted? Does the position (lambda) of the maximal absorption peaks cha
Marianna [84]

After the dillution of the solution, the wavelength of maximum absorption is decreased.

<h3>What is the wavelength of maximum absorption?</h3>

The wavelength of maximum absorption is the wavelength at which the solution absorbs the maximum amount of light. It is usually shown as a hump in the spectrum.

When the starting concentration of the  K2Cr2O7 is diluted, the wavelength of maxium absorption decreases.

Learn more about maximum absorption: brainly.com/question/26610701

6 0
2 years ago
What would the corresponding
ad-work [718]

Answer:

7,9,11

Explanation:

this is because water includes 0H, which would mean that it is more than 6

4 0
1 year ago
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