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2 years ago

Chem pls help and look at pics

Chemistry

1 answer:

ser-zykov [4K]2 years ago

6 0

Answer:

1. 16 protons, 18 electrons, 16 neutrons

2. Ba (2+) + 2 NO3 (-) + 2 Na (+) + SO4 (-) = 2 Na (+) + 2 NO3 (-) + BASO4

Explanation:

1. By looking at the number in the top left corner, we know the mass is 32. And by looking at the number in the bottom left, we know that we have 16 protons. Now the way to find neutrons is to subtract the number of protons from the mass (32-16) which will give us 16 neutrons. Now the electrons are a bit tricky. Usually, atoms have the same number of protons and electrons, hence why atoms don't usually have a charge. However, in this case we have a charge of 2- (as seen in the top right corner) so we need to add two to the number of protons to find our number of electrons (electrons are negatively charged, so if there are more of them the atom will have an overall negative charge) and when we do that we get 18. So the final answer is 16 protons, 18 electrons, and 16 neutrons.
2. This one I'm not 100% sure on since the pictures are kinda wonky but essentially the way net ionic equations are written is that whatever is aqueous/soluble (aq) will be written separate from whatever it was bonded to with the charge shown, but solids (s), liquids (l), and gases (g) are written still bonded without the charge being shown. So in this case, everything in the reaction is aqueous except for the BaSO4 product. The parentheses are used to show charges, but won't be written in an actual equation, and the equal sign is the same as the arrow. So you're equation is written as Ba (+) + 2 NO3 (-) + 2 Na (+) + So4 (2-) = 2 Na (+) + NO3 (-) + BaSO4.
Hope this helps! :)

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Nataly_w [17]

Answer: 1.61 x 10⁴ kPa

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Pi = xi P

where Pi is the partial pressure of the gas i, xi is the mole fraction of the gas i in the gas mixture and P is the total pressure.

The mole fraction is defined as the quotient between the moles of solute (ni) and the total moles of the mixture (nt), which is calculated by adding the moles of all its components:

xi = $\frac{n_{i} }{n_{t} }$

In the Trimix 10/50 mix you have 10% oxygen, 50% helium and 40% nitrogen.

To calculate the total number of moles of the mixture and thus determine the molar fraction of helium, we consider 100 g and calculate the number of moles that represent 10 g of O₂ (n₁), 50 g of He (n₂) and 40 g of N₂ (n₃):

n₁ = 10 g x $\frac{1 mol}{31.998 g}$ = 0.313 mol

n₂ = 50 g x $\frac{1 mol}{8.005 g}$ = 6.246 mol

n₃ = 40 g x $\frac{1 mol}{28.013 g}$ = 1.428 mol

Then the total number of moles (nt) will be:

nt = n₁ + n₂ + n₃ = 0.313 mol + 6.246 mol +1.428 mol

nt = 7,987 mol

Then, the mole fraction of helium (x₂) in the mixture will be,

x₂ = $\frac{6.246 mol}{7.987 mol}$ = 0.78

and the partial pressure of helium in the mixture, according to Dalton's law, will be:

P₂ = x₂ P = 0.78 x 2.07 x 10⁴ kPa

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Low pH (0.0 or close) corresponds to strong acids
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