What is the gram formula mass of Li 2 SO 4 ? Li2 + S + O4 = 13.88 + 32.06 + 63.996 = 109.94 molar mass of Li2SO4

a 25.0-ml volume of a sodium hydroxide solution requires 19.6 ml of a 0.189 m hydrochloric acid for neutralization. a 10.0- ml v

Rashid [163]

Concentration of NaOH = 0.148 molar, M

Concentration of H3PO4 = 0.172 molar, M

Concentration x Volume will give the number of moles of solute in that volume. C*V = moles

Concentration has a unit of (moles/liter). When multiplied by the liters of solution used, the result is the number of moles.

Original HCl solution: (0.189 moles/L)*(0.0196 L)= 0.00370 moles of HCl

The neutralization of 25.0 ml of sodium hydroxide, NaOH, requires 0.00370 moles of HCl. The reaction is:

NaOH + HCl > NaCl and H2O

This balanced equation tells us that neutralization of NaOH with HCl requires the same number of moles of each. We just determined that the moles of HCl used was 0.00370 moles. Therefore, the 25.0 ml solution of NaOH had the same number of moles: 0.00370 moles NaOH.

The 0.00370 moles of NaOH was contained in 25.0 ml (0.025 liters). The concentration of NaOH is therefore:

(0.00370 moles of NaOH)/(0.025 L) = 0.148 moles/liter or Molar, M

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The phosphoric acid problem is handled the same way, but with an added twist. Phosphoric acid is H3PO4. We learn the 34.9 ml of the same NaOH solution (0.148M) is needed to neutralize the H3PO4. But now the acid has three hydrogens that will react. The balanced equation for this reaction is:

H3PO4 + 3NaOH = Na3PO4 + 3H2O

Now we need three times the moles of NaOH to neutralize 1 mole of H3PO4.

The moles of NaOH that were used is:

(0.148M)*(0.0349 liters) = 0.00517 moles of NaOH

Since the molar ratio of NaOH to H3PO4 is 3 for neutralization, the NaOH only neutralized (0.00517)*(1/3)moles of H3PO4 = 0.00172 moles of H3PO4.

The 0.00172 moles of H3PO4 was contained in 10.0 ml. The concentration is therefore:

(0.00172 moles H3PO4)/(0.010 liters H3PO4)

Concentration of H3PO4 = 0.172 molar, M

5 0

1 year ago

Two hydrogen atoms covalently bond to form a hydrogen molecule.

ankoles [38]

Answer:

B

Explanation:

the energy of two separate hydrogen atoms decreases as they approach each other, and the single electrons on each atom are shared to form a covalent bond.

7 0

3 years ago

How do the lengths of day contrast for the summer solstice and winter solstice?

amm1812

When it is tilted away from the Sun, it is winter in the northern hemisphere. In between we have autumn and spring. The day that the Earth's North Pole is tilted closest to the sun is called the summer solstice. This is the longest day (most daylight hours) of the year for people living in the northern hemisphere.

3 0

3 years ago

Identify whether longhand notation or noble-gas notation was used in each case below.

n200080 [17]

Answer:

The given electronic configuration is long hand notation.

Explanation:

Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.

Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.

The given electronic configuration of potassium (K):

The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.

6 0

3 years ago

If you bang on a large metal gong with a stick, producing a loud sound that can be heard by your friend down the street, how doe

Gennadij [26K]

Answer:

c

Explanation:

3 0

3 years ago