Questions: Solutes, solvents and solutions
The Amazing World of Solutes, Solvents, and Solutions18 min readLesson 5 of 5
Q1. Define solution, solute and solvent with one example.
Answer (English): A solution is a uniform mixture of two or more substances. In a solid-liquid solution, the solid component is the solute and the liquid component is the solvent. For example, in salt water, salt is the solute and water is the solvent, and the salt is dissolved in the water.
Hinglish: Solution do ya zyada substances ka uniform mixture hai. Solid-liquid solution mein solid component solute aur liquid component solvent hota hai. Jaise salt water mein salt solute hai aur paani solvent, aur salt paani mein ghul jaata hai.
Q2. How are solute and solvent decided when two liquids are mixed?
Answer (English): When two liquids mix to form a solution, the liquid present in the smaller amount is called the solute and the liquid present in the larger amount is called the solvent. The rule is about quantity, not about strength or thickness. For example, a small amount of acetic acid in a large amount of water makes a solution in which water is the solvent and acetic acid is the solute.
Hinglish: Jab do liquids mil kar solution banati hain, kam amount wali liquid solute aur zyada amount wali liquid solvent kehlati hai. Ye rule amount ka hai, strength ya thickness ka nahi. Jaise thoda sa acetic acid zyada paani mein mile to paani solvent aur acetic acid solute hota hai.
Q3. Differentiate between a saturated and an unsaturated solution, using the salt activity.
Answer (English): An unsaturated solution has not reached its limit at that temperature, so more solute can still dissolve in it. A saturated solution has dissolved as much solute as it can at that temperature, so any extra solute stays undissolved and settles at the bottom. In the salt activity, the first spoons of salt dissolve completely, giving an unsaturated solution. After a few more spoons, the salt stops dissolving and collects at the bottom, showing that the solution has become saturated at that temperature.
Hinglish: Unsaturated solution mein us temperature par aur solute ghul sakta hai. Saturated solution mein itna solute ghul chuka hota hai jitna us temperature par ghul sakta hai, isliye extra solute ghulta nahi aur neeche jam jaata hai. Salt activity mein shuru ke spoons poori tarah ghulte hain, solution unsaturated hota hai. Kuch aur spoons ke baad salt ghulna band ho jaata hai aur neeche jama ho jaata hai, matlab solution us temperature par saturated ban gaya.
Q4. What is concentration? Differentiate dilute and concentrated solutions with an example.
Answer (English): Concentration tells how much solute a fixed quantity of solution or solvent contains. A solution with less solute is called dilute, and one with more solute is called concentrated. These terms are relative. In the salt activity, the solution made with one spoon of salt is dilute compared with the solution made with three or four spoons in the same amount of water.
Hinglish: Concentration fixed quantity ke solution ya solvent mein present solute ki amount hai. Kam solute wala solution dilute aur zyada solute wala concentrated kehlata hai. Ye terms relative hain. Salt activity mein ek spoon salt wala solution teen-chaar spoon salt wale solution ke muqable dilute hota hai.
Q5. What is solubility? How does temperature affect the solubility of most solids?
Answer (English): Solubility measures the most solute a fixed quantity of solvent can hold at a given temperature. For most solids, solubility increases as the temperature rises. In the baking soda activity, some solid remained undissolved at 20 °C, but it dissolved when the water was heated to 50 °C, and even more baking soda could be dissolved at 70 °C. A solution that is saturated at a low temperature can therefore become unsaturated when it is warmed.
Hinglish: Solubility maximum solute ki amount hai jo fixed quantity ke solvent mein ek particular temperature par ghul sakti hai. Zyadatar solids ki solubility temperature badhne par badhti hai. Baking soda activity mein 20 °C par kuch solid ghula nahi tha, par 50 °C par ghul gaya, aur 70 °C par aur zyada ghul sakega. Isliye kam temperature par saturated solution garam karne par unsaturated ban sakta hai.
Q6. How does warming water change the solubility of gases in it? Why does this matter for aquatic life?
Answer (English): The solubility of most gases in water decreases as the temperature rises. Oxygen dissolves only slightly in water, but that dissolved oxygen is what aquatic plants, fish and other organisms use. Cold water holds more oxygen than warm water. When water warms up, less oxygen remains dissolved, so the oxygen available to aquatic life falls.
Hinglish: Temperature badhne par zyadatar gases ki paani mein solubility ghatti hai. Oxygen paani mein thodi hi ghulti hai, par yahi dissolved oxygen aquatic plants, fish aur doosre organisms ke kaam aati hai. Thanda paani zyada oxygen rakhta hai.
Garam paani mein kam oxygen ghulti hai, isliye aquatic life ko kam oxygen milti hai.
Q7. Differentiate between mass and weight. Which instrument measures mass?
Answer (English): Mass is the quantity of matter in an object and is measured in grams and kilograms. Weight is the force with which the Earth attracts the object and is measured in newtons. A balance is the instrument used to measure mass, even though most balances actually measure weight and their scales are marked in mass units.
Hinglish: Mass object mein matter ki quantity hai, gram aur kilogram mein. Weight woh force hai jisse Earth object ko apni taraf kheenchti hai, newton mein. Mass naapne ka instrument balance hai, halanki zyadatar balances asal mein weight naapte hain aur unke scale mass units mein marked hote hain.
Q8. How is the volume of a liquid measured using a measuring cylinder?
Answer (English): A measuring cylinder is a narrow, tall, transparent cylinder with a scale for reading the volume. Pour the liquid in slowly, then read the mark at the bottom of the meniscus for colourless liquids, keeping the eye level with the meniscus. A dropper can adjust the level. The smallest division depends on the capacity, so a 100 mL cylinder can read 1 mL while a 25 mL cylinder can read 0.1 mL.
Hinglish: Measuring cylinder patla, lamba, transparent cylinder hai jis par volume ka scale hota hai. Liquid dheere daalo, phir colourless liquids ke liye meniscus ke bottom par mark padho, aankh meniscus ke level par rakho. Dropper se level adjust kar sakte hain. Sabse chhoti division capacity par depend karti hai: 100 mL cylinder 1 mL padh sakta hai, 25 mL cylinder 0.1 mL.
Q9. What is density? A block has a mass of 24 g and a volume of 8 cm³. Calculate its density.
Answer (English): Density tells the mass in one unit of volume, calculated as mass divided by volume. For the block, density = 24 g ÷ 8 cm³ = 3 g/cm³. Water has a density of about 1 g/cm³, so this block is three times denser than water. Its relative density with respect to water is 3. Relative density is a pure number and has no units.
Hinglish: Density ek unit volume mein present mass hai, jise mass ÷ volume se nikala jaata hai. Block ke liye density = 24 g ÷ 8 cm³ = 3 g/cm³. Paani ki density kareeb 1 g/cm³ hoti hai, isliye ye block paani se teen guna dense hai. Paani ke respect mein iski relative density 3 hai. Relative density sirf ek number hai, iski koi unit nahi hoti.
Q10. Why does ice float on water? Give one more example of floating explained by density.
Answer (English): Ice floats because it is less dense than liquid water. Water has its highest density at 4 °C. When water freezes, its particles arrange themselves so that the same mass occupies a larger volume, so ice expands and its density falls below that of water. A bamboo raft floats for a similar reason: bamboo is light and hollow, so the raft's overall density is lower than that of water.
Hinglish: Ice isliye tairti hai kyunki woh liquid paani se kam dense hai. Paani ki density 4 °C par sabse zyada hoti hai. Paani jamne par uske particles aise arrange hote hain ki same mass zyada volume gher leta hai, isliye ice expand hoti hai aur uski density paani se kam ho jaati hai. Bamboo raft bhi isi wajah se tairta hai: bamboo halka aur hollow hota hai, isliye raft ki overall density paani se kam hoti hai.
The quick check below has five multiple choice questions on solutions, solubility and density. Each one comes with a short explanation, so take the quiz and see which topics need another read.