50 points!!! PLZ HELP 1. Which solvent, water or carbon tetrachloride, would you choose to dissolve each of the following? Why?

explain one or two things that adversely (negatively) affect the Earth's environment. How do you know that these things you're d

zimovet [89]

Answer:

Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.

8 0

3 years ago

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How many miles are in 8.73 *10^25 atoms of boron

Mnenie [13.5K]

The correct question is: How many moles are in $8.73 \times 10^{25}$ atoms of boron.

Answer: There are 145 moles present in $8.73 \times 10^{25}$ atoms of boron.

Explanation:

According to the mole concept, there are $6.022 \times 10^{23}$ atoms present in one mole of every substance.

Hence, number of moles present in $8.73 \times 10^{25}$ atoms is calculated as follows.

$Moles = \frac{8.73 \times 10^{25}}{6.022 \times 10^{23}}\\= 1.45 \times 10^{2}\\= 145 mol$

Thus, we can conclude that there are 145 moles present in $8.73 \times 10^{25}$ atoms of boron.

5 0

3 years ago

The copper(I) ion forms a chloride salt (CuCl) that has Ksp = 1.2 x 10-6. Copper(I) also forms a complex ion with Cl-:Cu+ (aq) +

Mnenie [13.5K]

Answer: (a) The solubility of CuCl in pure water is $1.1 \times 10^{-3} M$ .

(b) The solubility of CuCl in 0.1 M NaCl is $9.5 \times 10^{-3} M$ .

Explanation:

(a) Chemical equation for the given reaction in pure water is as follows.

$CuCl(s) \rightarrow Cu^{+}(aq) + Cl^{-}(aq)$

Initial: 0 0

Change: +x +x

Equilibm: x x

$K_{sp} = 1.2 \times 10^{-6}$

And, equilibrium expression is as follows.

$K_{sp} = [Cu^{+}][Cl^{-}]$

$1.2 \times 10^{-6} = x \times x$

x = $1.1 \times 10^{-3} M$

Hence, the solubility of CuCl in pure water is $1.1 \times 10^{-3} M$ .

(b) When NaCl is 0.1 M,

$CuCl(s) \rightarrow Cu^{+}(aq) + Cl^{-}(aq)$ , $K_{sp} = 1.2 \times 10^{-6}$

$Cu^{+}(aq) + 2Cl^{-}(aq) \rightleftharpoons CuCl_{2}(aq)$ , $K = 8.7 \times 10^{4}$

Net equation: $CuCl(s) + Cl^{-}(aq) \rightarrow CuCl_{2}(aq)$

$K' = K_{sp} \times K$

= 0.1044

So for, $CuCl(s) + Cl^{-}(aq) \rightarrow CuCl_{2}(aq)$

Initial: 0.1 0

Change: -x +x

Equilibm: 0.1 - x x

Now, the equilibrium expression is as follows.

K' = $\frac{CuCl_{2}}{Cl^{-}}$

0.1044 = $\frac{x}{0.1 - x}$

x = $9.5 \times 10^{-3} M$

Therefore, the solubility of CuCl in 0.1 M NaCl is $9.5 \times 10^{-3} M$ .

7 0

3 years ago

PLEASE HELP ASAP!!!

xz_007 [3.2K]

Answer: 207.24

Explanation: Atomic mass = no of protons + no of neutrons

1) 82 protons, 122 neutrons , mass number= 82+122 = 204

2) 82 protons, 125 neutrons, mass number= 82+125 = 207

3) 82 protons, 124 neutrons, mass number= 82+124 = 206

4) 82 protons, 126 neutrons, mass number= 82+126 = 208

Average atomic mass of an element = $\sum(\text{atomic mass of an isotopes}\times {{\text {fractional abundance}}$

Average atomic mass of given element = $(204\times 0.014+207\times 0.221 +206\times 0.241+208\times 0.524)=207.24$

The approximate atomic mass of lead is 207.24.

8 0

4 years ago

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Oxygen has 8 positively-charged protons. What is the number of negatively-charged electrons in an atom of Oxygen?

Gala2k [10]

Answer:

Answer 9: Oxygen is atomic number 8 on the periodic table, which means it has 8 protons!

Explanation:

Oxygen's 8 electrons are negatively charged, and they orbit the atomic nucleus and balance the positive charge of the 8 protons. The positive charge of 1 proton exactly cancels the negative charge of 1 electron.

8 0

3 years ago

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