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4 years ago

The periodic table was developed based upon the work of which scientist?

2 answers:

8 0

Mendeleev organized and constructed the periodic table of elements. And ordered the elements into increasing atomic number.

sveticcg [70]4 years ago

5 0

C. Moosely
It is the Answer to your question.

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Determine the molecular and empirical formulas for the substance shown in the ball-and-stick model below.

notka56 [123]

Molecular formula: C8H6N2

Empirical formula: C4H3N

8 0

3 years ago

What is effective nuclear charge?

Amiraneli [1.4K]

Answer:

The effective nuclear charge (often symbolized as Zeff or Z*) is the net positive charge experienced by an electron in a multi-electron atom. The term “effective” is used because the shielding effect of negatively charged electrons prevents higher orbital electrons from experiencing the full nuclear charge.

Explanation:

6 0

3 years ago

A 5.325g sample of methyl benzoate, a compound in perfumes , was found to contain 3.758 g of carbon, 0.316 g of hydrogen, and 1.

Alexxandr [17]

Answer: The empirical and molecular formula of the compound is $C_4H_4O$ and $C_8H_8O_2$ respectively

Explanation:

We are given:

Mass of C = 3.758 g

Mass of H = 0.316 g

Mass of O = 1.251 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{3.758g}{12g/mole}=0.313moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.316g}{1g/mole}=0.316moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{1.251g}{16g/mole}=0.078moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.078 moles.

For Carbon = $\frac{0.313}{0.078}=4.01\approx 4$

For Hydrogen = $\frac{0.316}{0.078}=4.05\approx 4$

For Oxygen = $\frac{0.078}{0.078}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : O = 4 : 4 : 1

The empirical formula for the given compound is $C_4H_4O$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 130 g/mol

Mass of empirical formula = 68 g/mol

Putting values in above equation, we get:

$n=\frac{130g/mol}{68g/mol}=1.9\approx 2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(2\times 4)}H_{(2\times 4)}O_{(2\times 2)}=C_8H_8O_2$

Hence, the empirical and molecular formula of the compound is $C_4H_4O$ and $C_8H_8O_2$ respectively

4 0

3 years ago

Question 6

hodyreva [135]

Answer:

0.00688 moles

Explanation:

The molarity ratio looks like this:

Molarity = moles / volume (L)

After you convert mL to L, you can plug the values into the equation and simplify to find moles.

27.5 mL / 1,000 = 0.0275 L

Molarity = moles / volume <----- Molarity ratio

0.250 M = moles / 0.0275 L <----- Insert values

0.00688 = moles <----- Multiply both sides by 0.0275

4 0

2 years ago

This is for my science class.

Kay [80]

Answer:

4 joules

Hope this helps if it does consider giving brainliest

Cya on the next one!

Explanation:

5 0

3 years ago

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