Acids and Bases

pHun Reactions - 10SCIE

2021

Akoranga 10 Mahi Tuatahi

Name or create these ionic compounds! Bonus, count up the number of each type of element in the atom.

1. Sodium Nitrate
2. Sodium Sulfate
3. Sodium Phosphate
4. $$MgN$$
5. $$CaS$$
6. $$FeI_{3}$$

Ngā Whāinga Ako

1. Explain the pH scale and use it to determine if a substances is an acid, base, or neutral
2. Can use a range of indicators to identify acids and bases

Write the date and ngā whāinga ako in your book

Acids

• Taste sour
• Are red-orange-yellow in universal indicator
• pH 0-6
• In lots of citrus fruits
• $$H^{+}$$ ions make a solution acidic!

Bases / Alkali

• Soapy/slippery
• Are blue-purple in universal indicator
• pH 8-14
• Used in cleaners commonly
• $$OH^{-}$$ ions make a solution basic/alkali!

Neutral

• In the middle of the scale is water
• Water has an equal amount (or no) $$H^{+}$$ and $$OH^{-1}$$ ions!
• It is green in universal indicator

Akoranga 16 Mahi Tuatahi

1. What is the name of element $$Ne$$?
2. What is the atomic number of element $$Ca$$?
3. How many electrons does the element $$C$$ have?
4. Draw an electron configuration diagram for an element with 17 electrons
5. What element has 17 electrons?
6. Protons are positive (T/F)
7. Electrons exist inside the nucleus of the atom (T/F)
8. Atoms are neutral overall (T/F)
1. What colours do acids turn universal indicator?
2. What ion causes a solution to be acidic?
3. Water will change the colour of litmus paper (T/F)
4. Sodium hydroxide is an acid (T/F)
5. Give the name of this ionic compound: $$CuSO_{4}$$
6. Write the formula of potassium phosphate
7. Red litmus paper goes blue in the presence of an acid (T/F)

Common Acids and Bases

• Acids
• Hydrochloric Acid ($$HCl$$)
• Sulphuric Acid ($$H_{2}SO_{4}$$)
• Nitric Acids ($$HNO_{3}$$)
• Citric Acid (in sour things)
• Bases
• Sodium Hydroxide ($$NaOH$$)
• Potassium Hydroxide ($$KOH$$)
• Barium Hydroxide ($$Ba(OH)_{2}$$)

Balancing Reactions

• When writing chemical formula, it is important that there are the same number of each atom on each side of the equation.
\begin{aligned} NaOH + HCl \rightarrow NaCl + H_{2}O \end{aligned}
• Pātai: How many of each atom on each side of the equation?

Neutralisation Reaction

A reaction between acid and base is called a neutralisation reaction.

\begin{aligned} acid + base &\rightarrow salt + water \newline \text{hydrochloric acid} + \text{sodium hydroxide} &\rightarrow \text{sodium chloride} + water \newline HCl + NaOH &\rightarrow NaCl + H_{2}O \end{aligned}