What is KUFCA? in science?

In the figure, which two lines appear to be parallel?

Ipatiy [6.2K]

I don’t understand. Is there a picture? Where are the options?

7 0

3 years ago

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How many atoms are in 5 grams of H2O?

mojhsa [17]

Hello!

We know that by the Law of Avogrado, for each mole of substance we have 6.02 * 10²³ atoms, if:

The molar mass of water (H2O)

H = 2 * (1u) = 2u

O = 1 * (16u) = 16u

---------------------------

The molar mass of H2O = 2 + 16 = 18 g / mol

If:

1 mol we have 6.02 * 10²³ atoms

1 mole of H2O we have 18 g

Then we have:

18 g ------------- 6.02 * 10²³ atoms

5 g -------------- x

$\dfrac{18}{5} = \dfrac{6.02*10^{23}}{x}$

$18*x = 5*6.02*10^{23}$

$18\:x = 3.01*10^{24}$

$x = \dfrac{3.01*10^{24}}{18}$

$\boxed{\boxed{x \approx 1.672*10^{23}\:atoms}}\end{array}}\qquad\checkmark$

I Hope this helps, greetings ... DexteR! =)

6 0

3 years ago

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How many molecules are in 1.28 mols of silicon dioxide

coldgirl [10]

Answer:

7.71x10^23 molecules

Explanation:

Avogadro's # = 6.022x10^23

1.28 mol SiO2 x 6.022x10^23/ 1 mol SiO2 = 7.71x10^23 molecules

8 0

2 years ago

An unknown compound with a molar mass of 223.94 g/mol consists of 32.18% c, 4.50% h, and 63.32% cl. find the molecular formula f

Dima020 [189]

The actual number of atoms of each element present in the molecule of the compound is represented by the formula known as molecular formula.

Molar mass of the unknown compound = 223.94 g/mol (given)

Mass of each element present in the unknown compound is determined as:

Mass of carbon, $C$ :

$\frac{32.18}{100}\times 223.94 = 72.06 g$

Mass of hydrogen, $H$ :

$\frac{4.5}{100}\times 223.94 = 10.08 g$

Mass of chlorine, $Cl$ :

$\frac{63.32}{100}\times 223.94 = 141.79 g$

Now, the number of each element in the unknown compound is determined by the formula:

$number of moles = \frac{given mass}{molar mass}$

Number of moles of $C$ :

$number of moles = \frac{72.06}{12} = 6.005 mole\simeq 6 mole$

Number of moles of $H$ :

$number of moles = \frac{10.08}{1} = 10.08 mole\simeq 10 mole$

Number of moles of $Cl$

$number of moles = \frac{141.79}{35.5} = 3.99 mole\simeq 4 mole$

Dividing each mole with the smallest number of mole, to determine the empirical formula:

$C_{\frac{6}{4}}H_{\frac{10}{4}}Cl_{\frac{10}{4}}$

$C_{1.5}H_{2.5}Cl_{1}$

Multiplying with 2 to convert the numbers in formula into a whole number:

So, the empirical formula is $C_{3}H_{5}Cl_{2}$ .

Empirical mass = $12\times 3+1\times 5+2\times 35.5 = 112 g/mol$

In order to determine the molecular formula:

n = $\frac{molar mass}{empirical mass}$

n = $\frac{223.94}{112} = 1.99 \simeq 2$

So, the molecular formula is:

$2\times C_{3}H_{5}Cl_{2} = C_{6}H_{10}Cl_{4}$

6 0

3 years ago

13. which of the following states of matter has no definite shape but does have a fixed volume? a. liquid b. solid c. gas d. ele

lutik1710 [3]

Gas im pretty sure. if not gas then liquid

5 0

3 years ago