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Ber [7]
2 years ago
12

What is this and explain why please:)

Chemistry
2 answers:
Yuliya22 [10]2 years ago
8 0

Answer:

C Atomic number

Explanation:

The question is typo it should be 19 is the____ of pottasium. The atomic number is the number on top

Alex777 [14]2 years ago
6 0
I don’t think would have like that to
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How many neutrons does a atom of cobalt have?
OverLord2011 [107]

Did you mean the atomic mass?


4 0
3 years ago
How many H2O molecules are in 183.2 grams of H20 gas?
jek_recluse [69]

Answer: There are 61.24 \times 10^{23} molecules present in 183.2 grams of H_{2}O gas.

Explanation:

Given: Mass = 183.2 g

Number of moles is the mass of substance divided by its molar mass.

As molar mass of water is 18 g/mol. Therefore, moles of H_{2}O are calculated as follows.

Moles = \frac{mass}{molar mass}\\= \frac{183.2 g}{18 g/mol}\\= 10.17 mol

According to the mole concept, there are 6.022 \times 10^{22} molecules present in one mole of a substance.

Hence, molecules present in 10.17 moles are calculated as follows.

10.17 mol \times 6.022 \times 10^{23}\\= 61.24 \times 10^{23}

Thus, we can conclude that there are 61.24 \times 10^{23} molecules present in 183.2 grams of H_{2}O gas.

6 0
3 years ago
he heat of fusion of tetrahydrofuran is . Calculate the change in entropy when of tetrahydrofuran melts at . Be sure your answer
lana [24]

Answer:

\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}

Explanation:

Hello.

In this case, given the heat of fusion of THF to be 8.5 kJ/mol and freezing at -108.5 °C, for the required mass of 5.9 g, we can compute the entropy as:

\Delta S=\frac{n*\Delta H}{T}

Whereas n accounts for the moles which are computed below:

n=5.9g*\frac{1mol}{72g} =0.082mol

Thus, the entropy turns out:

\Delta S=\frac{0.0819mol*8.5 kJ/mol}{(-108.5+273.15)K}\\\\\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}

Best regards.

3 0
3 years ago
A sample of a compound contains 32.0 g C and 8.0 g H. Its molar mass is 30.0 g/mol. What is the compound’s molecular formula
Grace [21]
The compound's molecular formula is C2H6. This is obtained by:
  
            mass             moles               divided by smallest moles
C          32g         32/12 = 2.67                                 1
H           8g           8/1.01 = 7.92                        approx. 3

Next, divide both terms by the smallest number of moles, 2.67. This gives 1 and 3. So the empirical formula is CH3 which has a molar mass of 15g/mol. Given the molar mass of the molecular formula as 30g/mole, we can calculate the factor by which to multiply the subscripts of CH3.

X = molar mass of molecular formula / molar mass of empirical formula = 30/15
X=2

So (CH3)2 is C2H6.
3 0
2 years ago
Which of the following is closest to the meaning of the term ancestor?
rjkz [21]

Answer:

I would say A

Explanation:

our ancestors are the people that lived long before us

8 0
3 years ago
Read 2 more answers
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