Acid

Substances which release hydrogen ions (H+ions) in aqueous solution or donates proton during chemical reaction are called acid. This note explains about types and properties of acid along with its uses.

Summary

Substances which release hydrogen ions (H+ions) in aqueous solution or donates proton during chemical reaction are called acid. This note explains about types and properties of acid along with its uses.

Things to Remember

  • Substances which release hydrogen ions (H+ions) in aqueous solution or donates proton during the chemical reaction are called acid.
  • On the basis of strength, acids are of two types. They are dilute acid and concentrated acid.
  • On the basis of their origin acids are of two types. They are organic acids and inorganic acids.
  • Fruits like lemon, grapes, vinegar etc. contain citric acid, tartaric acid, acetic acid respectively and they are edible acids.
  • Hydrochloric acid, sulphuric acid, nitric acid are strong acids and corrosive  in nature. So, it is dangerous to taste mineral acids.
  • Acids are used to make chemical fertilizers like (NH4)SO4, NH4NO3, etc.
  • Tartaric acid is used in baking powder.

MCQs

No MCQs found.

Subjective Questions

Q1:

Find the area of the given triangle.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>\(\angle PRQ = \angle PQR = 75&deg;\\ PR = 8 cm \\ [\therefore PQ = PR] \)</p> <p>\begin{align*} \angle PQR + \angle PRQ + \angle QPR &amp;= 180&deg;\\ \angle QPR &amp;= 180&deg; - 75&deg; - 75&deg;\\ \angle QPR &amp;= 30&deg;\\ Area \:of\: \Delta PQR = ? \\ Area \: of \: \Delta PQR &amp;= \frac{1}{2}PQ \times PR \:\: sin \angle QPR \\ &amp;= \frac{1}{2} \times 8 \times 8 \times sin30&deg; \\ &amp;= 32 \times \frac{1}{2}\\ &amp;= 16 \: cm^2 \:\: _{Ans} \end{align*}</p>

Q2:

In the figure \(\Delta PQR \), PQ = 6 cm , QR = 8 cm, \(\angle Q = x°\:, \angle R =45° \: and \: \angle P = x+45°.\) Find the area of \(\Delta PQR\)

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>PQ = 6 cm <br>QR = 8 cm<br>\(\angle Q = x&deg;\)<br>Area of \(\Delta PQR\) = ?</p> <p>\begin{align*} x+x+75+45&amp;=180&deg;\\ or, 2x &amp;= 180&deg;-120&deg;\\ or, x &amp;= \frac{60}{2}\\ \therefore x &amp;= 30&deg; \end{align*}</p> <p>\begin{align*} Area \: of\: \Delta PQR &amp;= \frac{1}{2} \times PQ \times QR \: sin \angle PQR\\ &amp;= \frac{1}{2} \times 6 \times 8 \times sin30&deg;\\ &amp;= 24 \times \frac{1}{2}cm^2 \\ &amp;= 12 \: cm^2 \:\:\:\: _{Ans}\end{align*}</p>

Q3:

In the given \( \Delta ABC, \angle ACB=30° , AC= 8cm  \) and the area of \(\Delta ABC \) is \(24cm^2.\) Find the measurement of BC. 

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>\(\angle ACB=30&deg;\\ AC= 8 cm \)<br>\(\text{Area of } \Delta ABC = 24cm^2\)<br>BC = ?</p> <p>\begin{align*} \text{Area of } \Delta ABC &amp;= \frac{1}{2}AC\times BC \: sin \angle ACB\\ 24&amp;=\frac{1}{2} \times 8 \times BC \times sin30&deg;\\ 24 &amp;= 4 \times BC \times \frac{1}{2}\\ \frac{24}{2} &amp;= BC\\ \therefore BC &amp;= 12 \: cm \:\:_{ans} \end{align*}</p>

Q4:

Find the area of \(\Delta PQR\) where, P=12 cm , r = 15cm and \(\angle PQR\) = 65° 

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>P = 12 cm<br>r = 15 cm<br>\(\angle PQR =65&deg;\)<br>Area of\(\Delta PQR\) = ?<br>\begin{align*} Area \: of \: \Delta PQR &amp;= \frac{1}{2}PQ \times QR \: sin \angle PQR\\ &amp;= \frac{1}{2} \times 15 \times 12 \times sin65&deg;\\ &amp;= 90 \times 0.906 \\ &amp;= 81.54cm^2 \:\:\: _{ans} \end{align*}</p>

Q5:

In the given \(\Delta ABC\), AC = 4 cm,  BC = 7 cm, \( \angle A = 110° \: and \: \angle B = 40°. \) Determine the area of  \( \Delta ABC. \)

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>AC = 4 cm<br>BC = 7 cm<br>\(\angle A = 110&deg; \\ \angle B = 40&deg;\\ \angle C = 180&deg; - 110&deg; - 40&deg; = 30&deg; \)<br><br>Now,</p> <p>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2}AC \times BC \times sin \angle ACB\\ &amp;= \frac{1}{2}\times 4 \times 7 \times sin30&deg;\\ &amp;= 14 \times \frac{1}{2}\\ &amp;= 7 \: cm^2 \: \: \: _{Ans} \end{align*}</p>

Q6:

In the given figure, find the area of \(\Delta PQR\)

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p>
<p>PR = 7 cm<br />QR = 8 cm<br />\(\angle PRQ\) = ?</p>
<p>\begin{align*} Area \: of \: \Delta PQR &amp;= \frac{1}{2} PR \times QR sin \angle PRQ\\ &amp;=\frac{1}{2} \times 7 \times 8 \times sin45&deg; \\ &amp;= 28 \times \frac{1}{\sqrt{2}}cm^2 \\ &amp;= 14\sqrt{2} \end{align*}</p>

Q7:

In the given figure, AB = 7 cm, BC = 16 cm and the area of \(\Delta ABC = 28 \sqrt{3} cm^2\) . Find the value of \(\angle ABC.\)

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>AB = 7 cm<br>BC = 16 cm<br>\(Area \: of \: \Delta ABC = 28 \sqrt{3} cm^2\)</p> <p>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2} \times AB \times BC \times sin \angle ABC \\ or, 28 \sqrt{3} &amp;= \frac{1}{2} \times 7 \times 16 \times sin \angle ABC\\ or, \frac{28\sqrt{3}}{7 \times 8} &amp;= sin \angle ABC \\ or, sin \angle ABC &amp;= \frac{\sqrt{3}}{2}\\ or, sin \angle ABC &amp;= sin 60&deg;\\ \therefore \angle ABC &amp;= 60&deg; \:\:\:\: _{ans} \end{align*}</p>

Q8:

The area of the given parallelogram ABCD is 48 square cm. If AB = 8 cm, BC = 12 cm. Find the value of \(\angle ABC\).

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>Area of Parallelogram ABCD = 48 \(cm^2\)<br>AB = 8 cm<br>BC = 12 cm<br>\(\angle ABC\) = ?<br>Construction: Join A and C.<br>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2} ABCD \:\:\: [\because \text{Diagonal bisect a parallelogram}] \\ &amp;= \frac{1}{2} \times 48\\ &amp;= 24 cm^2 \end{align*}</p> <p>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2} AB \times BC \times sin \angle ABC\\ 24 &amp;= \frac{1}{2} \times 8 \times 12 \times sin \angle ABC \\ or, \frac{24}{4 \times 12} &amp;= sin \angle ABC \\ or, sin \angle ABC &amp;= \frac{1}{2} \\ or, sin \angle ABC &amp;= Sin 30&deg;\\ \therefore \angle ABC &amp;= 30&deg; \:\:\:\: _{Ans} \end{align*}</p>

Q9:

In the given figure AB = 10 cm, BC = 6 cm and \(\angle ABC = 60°.\) Find the area of parallelogram ABC.

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>AB = 10 cm<br>BC = 6 cm<br>\(\angle ABC = 60&deg;\)<br>Area of parallelogram ABCD = ?<br>Construction: Join AC</p> <p>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2} AB \times BC \: Sin \angle ABC \\ &amp;= \frac{1}{2} \times 10 \times 6 \times sin60&deg;\\ &amp;= 30 \times \frac{\sqrt{3}}{2} cm^2 \\ &amp;= 15\sqrt{3} \: cm^2 \: \: \: _{Ans} \end{align*}</p>

Q10:

In the given figure, AB = 6 cm, BC = 8 cm and \(\angle ABC = 60° \). Find the area of ABCD.

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>Ab = 6 cm<br>BC = 8 cm<br>\(\angle ABC \) = 60&deg;<br>Area f ABCD = ?<br>Construction : Join AC</p> <p>\begin{align*} Area \: of \: \Delta ABC &amp;= \frac{1}{2} AB \times BC \times sin \angle ABC \\ &amp;= \frac{1}{2} \times 6 \times 8 \times sin60&deg;\\ &amp;= 24 \times \frac{\sqrt{3}}{2}\\ &amp;= 12\sqrt{3} \:\:\:\: cm^2 \\ \\ Area \: of \: parallelogram\: ABCD &amp;= 2 Area \: of\: \Delta ABC \\ &amp;= 2 \times 12\sqrt{3} \\ &amp;=24\sqrt{3} \:cm^2 \:\:\:_{ans} \end{align*}</p>

Q11:

In the given diagram, \(\Delta BPC \) is an equilateral triangle and ABCD is a rhombus. If the area of APCD is \(27\sqrt{3} cm^2\), find the length of AB.

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>\(\angle CBP =60&deg;\) \(\:\:\:\:\: \) [\(\because\) Angle of equilateral]<br>\(\angle BAD = \angle CBP = 60&deg; \:\:\:\:\: [\because\) Corresponding angles ]<br>Construction : Join points B and D <br>AB = AD = CD = BC = BP = PC</p> <p>\begin{align*} Area \: of\: \Delta ABD &amp;= \frac{1}{2} AD \times AB \: Sin60&deg;\\ &amp;= \frac{1}{2} AD \times AB \times \frac{\sqrt{3}}{2} \\ &amp;= \frac{\sqrt{3}}{4} AB^2\\ Area \: of \: \Delta BCD &amp;= Area \: f \: \Delta ABD \\ &amp;= \frac{\sqrt{3}}{4} AB^2\:\:\:\:\: [\because BD \: bisect \: the \: rhombus \: ABCD ]\\ Area \: of\: \Delta BCP &amp;= \frac{1}{2} \times BC \times BP \times Sin60&deg;\\ &amp;= \frac{1}{2} \times AB \times AB \times \frac{\sqrt{3}}{4}\\ &amp;= \frac{\sqrt{3}}{4} AB^2 \\ Area \: of \: \Delta APCD &amp;= Area \: of\: \Delta ABD + Area \: of\: \Delta BCD + Area \: of\: \Delta BCP\\ 27\sqrt{3} &amp;= \frac{\sqrt{3}}{4} AB^2 + \frac{\sqrt{3}}{4} AB^2 + \frac{\sqrt{3}}{4} AB^2 \\ or, 27\sqrt{3} &amp;= \frac{\sqrt{3}AB^2 +\sqrt{3}AB^2+\sqrt{3}AB^2}{4} \\ or, 27\sqrt{3} &amp;= \frac{3\sqrt{3}AB^2}{4}\\ or, AB^2 &amp;= \frac{27\sqrt{3}\times 4}{3\sqrt{3}}\\ or, AB^2 &amp;= 36\\ or, AB^2 &amp;= 6^2\\ \therefore AB &amp;= 6 \: cm \end{align*}</p>

Q12:

In the given \(\Delta XYZ \) , XY = YZ = 12 cm & \(\angle XYZ = 30°,\) find the area of \(\Delta XYZ \)

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Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p><strong>Solution:</strong></p> <p>XY = YZ = 12 cm<br>\(\angle XYZ = 30&deg;\)<br>Area of \(\Delta XYZ\) = ?</p> <p>\begin{align*} Area \: of \: \Delta XYZ &amp;= \frac{1}{2} \times XY \times YZ \times sin \angle XYZ \\ &amp;= \frac{1}{2} \times 12 \times 12 \times sin30&deg; \\ &amp;= 6 \times 12 \times \frac{1}{2} \\ &amp;= 36 \: cm^2 \:\:\: _{Ans} \end{align*}</p>

Videos

Area of a Triangle - MathHelp.com
HOW TO FIND THE AREA OF A TRIANGLE: THE EASY WAY!
Acid

Acid

The chemical substance that releases hydrogen ion/s (H+ion/s) in aqueous solution or donates proton/s during chemical reaction is called an acid.

Examples:

HCl (Hydrochloric acid): H++ Cl-
HNO3 (Nitric acid): H+ + NO3-

Types of Acids

On the basis of strength, acids are of two types:

  1. Dilute acids:Those acids that release relatively less concentration of hydrogen ions in their aqueous solution are called dilute acids.
  2. Concentrated acids:Those acids that release relatively more concentration of hydrogen ions in their aqueous solution are called concentrated acid. Most of the mineral acids are concentrated acid.

Similarly, on the basis of their origin, acids are of two types:

  1. Organic acids: Those acids which can be extracted from living beings are called organic acids. Example: citric acid, tartaric acid, formic acid.
  2. Inorganic acids: Those acids which are obtained from the minerals are called inorganic acid. They are Hydrochloric acid (HCl), Nitric acid (HNO3) and Sulphuric acid (H2SO4).

Properties of Acid

  1. Acidshavesour taste. But acids like stearic acid, boric acid, may not have the sour taste. Fruits like lemon, grapes, vinegar etc. contain citric acid, tartaric acid, acetic acid respectively and they are edible acids.Hydrochloric acid, sulphuric acid, nitric acid are strong acids and are in nature. So, it is dangerous to taste mineral acids.

  2. The acids turn blue litmus paper into red,the light yellow color of methyl orange into red. They are neutral to phenolphthalein.

  3. Acid reacts with thebase, in which characteristics of both are destroyed or neutralized and salt and water are given out. NaOH + HCl → NaCl + H2O


    Fig: Sodium chloride (Salt used in our food)

  4. They give off hydrogen ion (H+) when dissolved in water. They conduct electricity. HCl → H+ + Cl-

Uses of Acids

    1. Sulfuric acid is used for making chemical fertilizers like (NH4) SO4, NH4NO3, etc.; drugs and detergents.
    2. Nitric acid are used in the manufacture of chemical fertilizer like NH4NO3,explosives and plastics.

      http://previewcf.turbosquid.com/Preview/2011/12/01__00_10_21/55.jpgba84edf9-a833-46de-bbf4-f0a38ac31518Large.jpg

      Fig: TNT (Explosive where nitric acid is used

      http://orj.cc/product_images/uploaded_images/Ammonium_Nitrate.jpg

      Fig: Ammonium nitrate (NH4NO3)
    3. Hydrochloric acid is used for bleaching purpose in textile industries for making glue, etc.
    4. Carbonic acid is used in soft drinks like soda water, coca cola, etc.
    5. Acetic acid is found in vinegar which is used for flavors.
    6. Tartaric acid is used in baking powder.

Fig: Baking powder

Lesson

Acid Base And Salt

Subject

Science

Grade

Grade 10

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