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2 years ago

Will give brainlist need answers asap

Chemistry

1 answer:

Serga [27]2 years ago

3 0

Answer:

40 g

Explanation:

Find the line labeled KClO3 (which might take you a min, theres a lot of lines here)

Notice that when the line creates a direct point, you can measure the exact temperature needed to dissolve a certain amount (like how they gave 30 degrees and it lined up perfectly with the 10 g line. )

Since its asking for the amount at 80 degrees, all you need to do is trace the line to the 80 degree point, and look at the grams. (notice it made a direct point, so there definitely should be any decimals or guesswork)

By reading the graph, you can tell that at 80 degrees, it dissolves 40 grams, and that is your answer.

Hope this helps :)

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Science.... <br> homework!

Leokris [45]

The answer to this question is 2 and 3

5 0

3 years ago

What element has 80 protons, 81 neutrons, 79 electrons?

Mariana [72]

Answer:

The element will be $^{161}_{80}X$

Explanation:

Given that,

Number of proton = 80

Number of neutron = 81

Number of electron = 79

We know that,

The atomic number is equal to the number of proton.

So, the atomic number is 80.

According to atomic number,

The element will be mercury.

We need to calculate the atomic mass

Using formula of atomic mass

$atomic\ mass=atomic\ number+number\ of\ neutron$

Put the value into the formula

$atomic\ mass=80+81$

$atomic\ mass=161$

We need to find the element

Using atomic mass and atomic number

$atomic\ mass\ number A=161$

$atomic\ number Z=80$

So, the element will be

$^{A}_{Z}X$

Put the value of A and Z

Hence, The element will be $^{161}_{80}X$

5 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.

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3 years ago

A reaction gives off 35.6 kJ how many calories is this?

tia_tia [17]

8.509 kilocalories I think

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Why are noble metals for example Rhodium, Palladium, Platinum, and Iridium largely used in chemical manufacturing as heterogeneo

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3 years ago