Are vegetable oil pure substance or mixture?

Phosphoric acid is a triprotic acid ( K a1 = 6.9 × 10 − 3 , K a2 = 6.2 × 10 − 8 , and K a3 = 4.8 × 10 − 13 ). To find the pH of

timama [110]

Answer:

Ka2 values should be used in obtaining pKa2 in the Henderson–Hasselbalch equation

Explanation:

During first dissociation from H3PO4 to H2PO4-, ka1 will be used, and from H2PO4-to HPO4-, ka2 values will be used, hence a buffer solution containing H2PO4-and HPO4-will use ka2 in obtaining pKa2 in the Henderson–Hasselbalch equation.

7 0

4 years ago

Please help Explain why a molecule that has polar bonds can be a polar molecule.

Zepler [3.9K]

Answer:

Explanation:

Well, obviously a molecule with polar bonds can be polar in itself. It's like saying I am an atheltic person who can just reach the basketball rim with my head and also I can dunk.

But if the question is how can a molecule that in non-polar have polar bonds, well, its because the polar bonds' dipole cancels each other out. It's like a tight rope. If a person pulls in one direction, it intuitively, the rope would go in that direction. However, if a person pulls in the other direction with the same amount of force, the rope stays still. This is the same case. Although molecules can have different electronegativities, the pull of electrons in one direction is cancelled out by a pull in the opposite direction, making the net dipole 0.

This is common for main VSERP shaped molecules like linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.

8 0

3 years ago

What is an ion-ion intermolecular force?

Dafna1 [17]

Answer: Ion-ion forces, also known as ionic bonding, are the simplest to understand. These forces arise from the electrostatic attraction between two ions with opposite charges.

Explanation:

3 0

3 years ago

An atom that has 13 protons and 15 neutrons is isotope of the element

wariber [46]

Answer=c

Atoms dont "lose" or "gain" protons, if they did, they'd be completely different elements. So basically, anything with 13 protons is a form of Aluminum.

7 0

3 years ago

What volume of air is needed to burn an entire 55-L (approximately 15-gal) tank of gasoline? Assume that the gasoline is pure oc

White raven [17]

Answer:

The volume of air required is 527,686.25L.

Explanation:

When the question says "burn", it refers to a combustion reaction, where a substance (in this case octane) reacts with oxygen to produce carbon dioxide and water.

Step 1: Write a balanced equation

Considering it is a combustion reaction, the balanced equation is:

C₈H₁₈ + 12.5 O₂ ⇄ 8 CO₂ + 9 H₂O

In this step, we start balancing elements that are present only in one compound on each side of the equation, namely, carbon and hydrogen.

To finish, it is important to count that there are the same number of atoms on both sides of the equation. In this case there are 8 atoms of Carbon, 18 atoms of Hydrogen and 25 atoms of Oxygen, so it is balanced.

Step 2: Find out the mass of C₈H₁₈

Since the balanced equation gives us information about the mass of C₈H₁₈ involved in the reaction, we need to find out how many grams we have.

The info we have is:

55 L of gasoline (assuming gasoline to be pure octane).
The density of octane is 0,70 g/cm³

Density relates mass and volume, so we can find out how many grams are represented by 55 L. Since the units used are different, first we need to convert liters into cm³. We use the conversión factor 1 L = 1000 cm³.

$55L.\frac{1000cm^{3} }{1L} =55000cm^{3}$

Since density = mass/volume, we can solve for mass:

$mass = density.volume=0.70\frac{g}{cm^{3} } .55,000cm^{3} =38,500g$

Step 3: Establish the theoretical relationship between the mass of octane and the moles of oxygen.

This relationship comes from the balanced equation.

For octane:

molar mass of C₈H₁₈ = molar mass of C . 8 + molar mass of H . 18 =

12 g/mol . 8 + 1g/mol . 18 = 114 g/mol

According to the balanced equation reacts 1 mol of octane, which means 114 grams of it.

For oxygen:

According to the balanced equation, 12.5 moles of oxygen react.

Then, the relationship is 114 g octane : 12.5 moles of oxygen

Step 4: Use the theorethical relationship to find the moles of oxygen that reacted

We use the mass of octane found in step 2 and apply the proper conversión factor.

$38,500g (octane) . \frac{12.5mol (oxygen)}{114g (octane)} = 4,221.49mol(oxygen)$

Step 5: Find out the volume of oxygen.

We know that 1 mol of any gas at room temperature occupies about 25 L. Then,

$4,221.49mol(oxygen).\frac{25L(oxygen)}{1mol(oxygen)} =105,537.25 L (oxygen)$

Step 6: Look the volume of air that contains such amount of oxygen

Given oxygen represents 20% of air, we can use that relationship to find the volume of air.

$105,537.25L(oxygen).\frac{100L(air)}{20L(oxygen)} =527,686.25L (air)$

4 0

4 years ago