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3 years ago

Which statement about one atom of an element identifies the element?(1) The atom has 1 proton.

1 answer:

vladimir2022 [97]3 years ago

3 0

<span>The answer is the option (1). the atom has 1 proton. This is because the number of protons is the characteristic that differentiates elements. Only the element hydorgen has 1 proton. It may have zero, one or two neutrons, but the only number for protons is 1. If the atom has a different number of protons it will not be the same element, That is why the periodic table is organized by atomic number which is the number of protons of the atoms of each element. </span>

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If 46.3 grams of acetylene are required to run a carbide lamp for 8 hours, how many moles of water are required

attashe74 [19]

Answer:

1.78 mol

Explanation:

Step 1: Write the balanced equation

CaC₂ + H₂O ⇒ C₂H₂ + CaO

Step 2: Calculate the moles corresponding to 46.3 g of C₂H₂

The molar mass of C₂H₂ is 26.04 g/mol.

46.3 g × 1 mol/26.04 g = 1.78 mol

Step 3: Calculate the moles of H₂O required to form 1.78 moles of C₂H₂.

The molar ratio of H₂O to C₂H₂ is 1:1. The moles of H₂O required are 1/1 × 1.78 mol = 1.78 mol.

7 0

3 years ago

How much energy (in J) is lost when a sample of iron with a mass of 26.4 g cools from 74.0 ∘C to 26.0 ∘C?

Greeley [361]

Answer:

$Q=-526.6J$

Explanation:

Hello,

In this case, for the computation of the energy loss when the cooling process is carried out, we use the shown below equation:

$Q=mCp\Delta T$

Whereas we need the mass, specific heat and change in temperature of iron within the process. Thus, the only value we need is the specific heat that is 0.444 J/(g°C), therefore, we compute the heat loss:

$Q=26.4g*0.444\frac{J}{g\°C}*(26.0\°C-74.0\°C)\\ \\Q=-526.6J$

Negative sign points out the loss due to the cooling.

Regards.

8 0

4 years ago

Part C<br> Number of molecules in 8.437x10-2 mol C6H6

N76 [4]

Answer:

There are $5.08\times 10^{22}\ \text{molecules of}\ C_6H_6$

Explanation:

In this problem, we need to find the number of molecules in $8.437\times 10^{-2}$ mol of $C_6H_6$ .

The molar mass of $C_6H_6$ is $6\times 12+1\times 6=78\ g/mol$

No of moles = mass/molar mass

We can find mass from above formula.

$m=n\times M\\\\m=8.437\times 10^{-2}\ mol\times 78\ g/mol\\\\m=6.58\ g$

Also,

No of moles = no of molecules/Avogadro number

$N=n\times N_A\\\\N=8.437\times 10^{-2}\times 6.023\times 10^{23}\\\\N=5.08\times 10^{22}\ \text{molecules}$

Hence, there are $5.08\times 10^{22}\ \text{molecules of}\ C_6H_6$

5 0

3 years ago

Help plz already know 1&2

Aleonysh [2.5K]

3. A
4. B
5. A
6. E
7. A
8. C
9. A
10. B
Some of these were guesses but they were educated guesses. Best of luck. If some of them are wrong I am sorry. <span />

3 0

3 years ago

Assume that you measured exactly 2.0 mL of the sodium chloride solution into a small test tube. How many moles of sodium chlorid

Lera25 [3.4K]

Answer:

0.034 mol (4dp)

Explanation:

Use the formula n = m/M where n= number of moles, m=mass in grams and M=molar mass in g/mol.

Therefore to find how many moles, divide the mass in grams (2) by the molar mass of sodium chloride which is 22.99+35.45

4 0

3 years ago

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