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2 years ago

A 12.2-g sample of X reacts with a sample of Y to form 78.9g of XY. what mass of Y reacted?

Chemistry

1 answer:

barxatty [35]2 years ago

3 0

Answer:

The answer to your question is: y = 66.7g

Explanation:

To solve this problem we must remember the Lavoisier law of conservation of mass, that stated that the mass can not be created or destroyed but it changes forms.

So, the mass of the reactants is equal to the mass of the products.

Process

x + y ⇒ xy

12.2g ? 78.9 g

12.2 g + y = 78.9g

y = 78.9 - 12.2

y = 66.7g

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Which molecule below has hydrogen bonding? Which molecule below has hydrogen bonding? H2 CH3CH2OH HCl CH4 all of the above

QveST [7]

Answer:

$CH_3CH_2OH$

Explanation:

Hydrogen bonding:-

Hydrogen bonding is a special type of the dipole-dipole interaction and it occurs between hydrogen atom that is bonded to highly electronegative atom which is either fluorine, oxygen or nitrogen atom.

Partially positive end of the hydrogen atom is attracted to partially negative end of these atoms which is present in another molecule. It is strong force of attraction between the molecules.

Thus, hydrogen must be linked to electronegative atom which is oxygen, fluorine and nitrogen which is in $CH_3CH_2OH$ and thus, it will shown hydrogen bonding.

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2 years ago

Excess magnesium reacts with 165.0 grams of hydrochloric acid in a single displacement reaction.

JulsSmile [24]

Answer:

The volume of hydrogen gas produced will be approximately 50.7 liters under STP.

Explanation:

Relative atomic mass data from a modern periodic table:

H: 1.008;
Cl: 35.45.

Magnesium is a reactive metal. It reacts with hydrochloric acid to produce

Hydrogen gas $\rm H_2$ , and
Magnesium chloride, which is a salt.

The chemical equation will be something like

$\rm ?\;Mg\;(s) + ?\;HCl \;(aq)\to ?\;H_2 \;(g)+ [\text{Formula of the Salt}]$ ,

where the coefficients and the formula of the salt are to be found.

To determine the number of moles of $\rm H_2$ that will be produced, first find the formula of the salt, magnesium chloride.

Magnesium is a group 2 metal. The oxidation state of magnesium in compounds tends to be +2.

On the other hand, the charge on each chloride ion is -1. Each magnesium ion needs to pair up with two chloride ions for the charge to balance in the salt, magnesium chloride. The formula for the salt will be $\rm MgCl_2$ .

$\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ ?\;MgCl_2\;(aq)$ .

Balance the equation. $\rm MgCl_2$ contains the largest number of atoms among all species in this reaction. Start by setting its coefficient to 1.

$\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ {\bf 1\;MgCl_2}\;(aq)$ .

The number of $\rm Mg$ and $\rm Cl$ atoms shall be the same on both sides. Therefore

$\rm {\bf 1\;Mg}\;(s) + {\bf 2\;HCl}\;(aq) \to ?\;H_2 \;(g)+ {1\;\underset{\wedge}{Mg}\underset{\wedge}{Cl_2}}\;(aq)$ .

The number of $\rm H$ atoms shall also conserve. Hence the equation:

$\rm {1\;Mg}\;(s) + {2\;\underset{\wedge}{H}Cl}\;(aq) \to {\bf 1\;H_2 \;(g)}+ {1\;MgCl_2}\;(aq)$ .

How many moles of HCl are available?

$M(\rm HCl) = 1.008 + 35.45 = 36.458\;g\cdot mol^{-1}$ .

$\displaystyle n({\rm HCl}) = \frac{m(\text{HCl})}{M(\text{HCl})} = \rm \frac{165.0\;g}{36.458\;g\cdot mol^{-1}} = 4.52576\;mol$ .

How many moles of Hydrogen gas will be produced?

Refer to the balanced chemical equation, the coefficient in front of $\rm HCl$ is 2 while the coefficient in front of $\rm H_2$ is 1. In other words, it will take two moles of $\rm HCl$ to produce one mole of $\rm H_2$ . $\rm 4.52576\;mol$ of $\rm HCl$ will produce only one half as much $\rm H_2$ .

Alternatively, consider the ratio between the coefficient in front of $\rm H_2$ and $\rm HCl$ is:

$\displaystyle \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}$ .

$\displaystyle n(\text{H}_2) = n(\text{HCl})\cdot \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}\;n(\text{HCl}) = \rm \frac{1}{2}\times 4.52576\;mol = 2.26288\;mol$ .

What will be the volume of that many hydrogen gas?

One mole of an ideal gas occupies a volume of 22.4 liters under STP (where the pressure is 1 atm.) On certain textbook where STP is defined as $\rm 1.00\times 10^{5}\;Pa$ , that volume will be 22.7 liters.

$V(\text{H}_2) = \rm 2.26288\;mol\times 22.4\;L\cdot mol^{-1} = 50.69\; L$ , or

$V(\text{H}_2) = \rm 2.26288\;mol\times 22.7\;L\cdot mol^{-1} = 51.37\; L$ .

The value "165.0 grams" from the question comes with four significant figures. Keep more significant figures than that in calculations. Round the final result to four significant figures.

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3 years ago

Linus pauling is famous for?

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Answer:

Linus Pauling became known as the founder of molecular biology due to his discovery of the spiral structure of proteins (Taton, 1964)

Explanation:

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3 years ago

In an ion with an unknown charge, the total mass of all the electrons was determined to be 2.19 ✕ 10−26 g, while the total mass

Ilya [14]

Answer:

$\large \boxed{\text{Fe$^{{2+}}$}}$

Explanation:

1. Number of electrons

$\text{Number of electrons} = 2.19 \times 10^{-26}\text{ g} \times \dfrac{\text{1 electron}}{9.109 \times 10^{-28}\text{ g}} = \text{24 electrons}$

2. Number of protons

$\text{Number of protons} = 4.34 \times 10^{-23}\text{ g} \times \dfrac{\text{1 proton}}{1.673 \times 10^{-24}\text{ g}} = \text{26 protons}$

3. Identify the ion

An atom with 26 protons is iron, Fe.

A neutral atom of iron would have 26 electrons.

The ion has only 24 electrons, so it has lost two. The ion must have a charge of +2.

$\text{The symbol for the ion is $\large \boxed{\textbf{Fe$^{\mathbf{2+}}$}}$}$

4 0

2 years ago

The s orbital can hold

malfutka [58]

Answer:

B. Two electrons

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2 years ago

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A 12.2-g sample of X reacts with a sample of Y to form 78.9g of XY. what mass of Y reacted?​

A 12.2-g sample of X reacts with a sample of Y to form 78.9g of XY. what mass of Y reacted?