Answer:
0.99%
Explanation:
The Henderson-Hasselbalch equation relates the ratio of the ionized to the non-ionized form of an acid as follows:
pH = pKa + log([A⁻]/[HA])
Inserting the values for pH and pKa and solving gives:
7.4 = 5.2 + log([A⁻]/[HA])
2 = log([A⁻]/[HA])
[A⁻]/[HA] = 100/1
The percentage of the weak acid in non-ionized form (HA) is then calculated:
[HA]/([A⁻] + [HA]) = 1/(100+1) x 100% = 0.99&
Answer:
14.3 mL
Explanation:
Assume the student used 0.113 g ascorbic acid and 0.0900 mol·L⁻¹ NaOH.
1. Balanced chemical equation.
The formula of ascorbic acid is H₂C₆H₆O₆ (MM = 176.12 g/mol).
However, for the balanced equation, let's write it as H₂A.
2. Moles of ascorbic acid
3. Moles of NaOH
The molar ratio is 2 mmol NaOH:1 mmol H₂A.
4. Volume of NaOH
Their lungs would try to expand to about 4 timed the normal volume which would force air into the various body tissues. this can cause a lung expansion injury and it could case air embolism. Air embolism is when air bubbles get trapped in blood vessels. This can lead to a blockage which will could be fatal.
Answer: 0.50 mole K2O
Explanation: To convert the mass of K2O to moles we will need to find the molar mass of K2O.
47.2 g K2O x 1 mole K2O / 94 g K2O
= 0.50 mole K2O
Answer:
Explanation:
To convert from representative particles to moles, Avogadro's Number: 6.02*10²³, which tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.
We can use it in a ratio.
Multiply by the given number of molecules.
Flip the ratio so the molecules of water cancel out.
Divide.
The original number of molecules has 2 significant figures: 3 and 1, so our answer must have the same. For the number we calculated, that is the tenth place. The 4 in the hundredth place tells us to leave the 1.
There are about 5.1 moles of water in 3.1*10²⁴ molecules of water.