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timofeeve [1]
3 years ago
8

Help please I am so lost my teacher is no help

Chemistry
1 answer:
uranmaximum [27]3 years ago
6 0

Answer:

B - CALCIUM

Explanation:

Hopes it helps

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What is the composition, in atom percent, of an alloy that consists of a) 5.5 wt% Pb and b) 94.5 wt% of Sn? Assume that the atom
Anastaziya [24]

Answer : The percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.

Explanation :

First we have to calculate the number of atoms in 5.5 wt% Pb and 94.5 wt% of Sn.

As, 207.2 g of lead contains 6.022\times 10^{23} atoms

So, 5.5 g of lead contains \frac{5.5}{207.2}\times 6.022\times 10^{23}=1.59\times 10^{22} atoms

and,

As, 118.71 g of lead contains 6.022\times 10^{23} atoms

So, 94.5 g of lead contains \frac{94.5}{118.71}\times 6.022\times 10^{23}=4.79\times 10^{23} atoms

Now we have to calculate the percent composition of Pb and Sn in atom.

\% \text{Composition of Pb}=\frac{\text{Atoms of Pb}}{\text{Atoms of Pb}+\text{Atoms of Sn}}\times 100

\% \text{Composition of Pb}=\frac{1.59\times 10^{22}}{(1.59\times 10^{22})+(4.79\times 10^{23})}\times 100=3.21\%

and,

\% \text{Composition of Sn}=\frac{\text{Atoms of Sn}}{\text{Atoms of Pb}+\text{Atoms of Sn}}\times 100

\% \text{Composition of Sn}=\frac{4.79\times 10^{23}}{(1.59\times 10^{22})+(4.79\times 10^{23})}\times 100=96.8\%

Thus, the percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.

6 0
3 years ago
3. How many moles are 1.707 x 10^24 atoms of carbon?
Paraphin [41]

Answer:

2.835 moles of carbon

Explanation:

By definition, there are 6.022x10^23 atoms (or compounds) in one mole.

Write and use this as a conversion factor:

(6.022x10^23 atoms)/mole

(1.707 x 10^24 atoms of carbon)/((6.022x10^23 atoms)/mole) = 2.835 moles carbon

8 0
2 years ago
If the pressure of 50.0 mL of oxygen gas at 100°C increases from 735 mm Hg to 925 mm Hg, what is
laila [671]

Answer: .039L

Explanation:

8 0
3 years ago
1b<br>Describe the terms below:<br>2. adiabatic process​
Ugo [173]

Answer:

defined as a process in which mo heat transfer take place

Explanation:

is a process which occurs without transferring heat /mass between the system and it's surrounding.

8 0
3 years ago
Nuclear reactions in a reactor produce a lot of thermal
Leokris [45]

Answer:

Heat flows from the reactor to the water

Explanation:

The thermal energy mentioned in the description is another way to say heat. The energy that is produced by the nuclear reactions leaves the reactor and enters the water, warming it.

The passage does <em>not </em>say that heat flows in the form of electricity, but rather that the turbines turned by the steam produce electricity.

The passage does <em>not </em>say that the steam produces the heat, but rather that the boiling of the water (caused by the heat) produces steam.

4 0
3 years ago
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