A. दो प्रकार तत्व और यौगिक/Two types elements and compounds
Step 1
Concept
Pure substances are classified into elements and compounds. Both have fixed composition.
Step 2
Why this answer is correct
The correct answer is A. दो प्रकार तत्व और यौगिक / Two types elements and compounds. Pure substances are classified into elements and compounds. Both have fixed composition.
Step 3
Exam Tip
शुद्ध पदार्थ elements और compounds में बाँटे जाते हैं। दोनों की composition निश्चित होती है।
Solvent is the component present in larger amount in a solution. Water is a common solvent in many solutions.
Step 2
Why this answer is correct
The correct answer is A. विलायक / Solvent. Solvent is the component present in larger amount in a solution. Water is a common solvent in many solutions.
Step 3
Exam Tip
Solvent solution में अधिक मात्रा वाला component होता है। पानी कई solutions में common solvent है।
B. बड़े कण समय के साथ settle हो सकते हैं/Large particles can settle with time
Step 1
Concept
In a suspension particles are large and can settle. Muddy water is an example.
Step 2
Why this answer is correct
The correct answer is B. बड़े कण समय के साथ settle हो सकते हैं / Large particles can settle with time. In a suspension particles are large and can settle. Muddy water is an example.
Step 3
Exam Tip
Suspension में कण बड़े होते हैं और settle हो सकते हैं। Muddy water इसका example है।
D. solution से बड़ा और suspension से छोटा/Larger than solution and smaller than suspension
Step 1
Concept
Colloid particles are of intermediate size. Therefore they generally do not settle quickly.
Step 2
Why this answer is correct
The correct answer is D. solution से बड़ा और suspension से छोटा / Larger than solution and smaller than suspension. Colloid particles are of intermediate size. Therefore they generally do not settle quickly.
Step 3
Exam Tip
Colloid particles intermediate size के होते हैं। इसलिए वे सामान्यतः जल्दी settle नहीं करते।
D. क्योंकि particles बहुत छोटे होते हैं/Because particles are very small
Step 1
Concept
Particles of a true solution are very small and do not scatter light. Therefore Tyndall effect is not seen.
Step 2
Why this answer is correct
The correct answer is D. क्योंकि particles बहुत छोटे होते हैं / Because particles are very small. Particles of a true solution are very small and do not scatter light. Therefore Tyndall effect is not seen.
Step 3
Exam Tip
True solution के particles बहुत छोटे होते हैं और light scatter नहीं करते। इसलिए Tyndall effect नहीं दिखता।
Sand particles are large and can be retained on filter paper. This is a common example of filtration.
Step 2
Why this answer is correct
The correct answer is B. रेत और पानी / Sand and water. Sand particles are large and can be retained on filter paper. This is a common example of filtration.
Step 3
Exam Tip
Sand particles बड़े होते हैं और filter paper पर रुक सकते हैं। यह filtration का common example है।
C. अघुलनशील ठोस और द्रव/Insoluble solid and liquid
Step 1
Concept
Filtration separates an insoluble solid from a liquid. Example is sand and water.
Step 2
Why this answer is correct
The correct answer is C. अघुलनशील ठोस और द्रव / Insoluble solid and liquid. Filtration separates an insoluble solid from a liquid. Example is sand and water.
Step 3
Exam Tip
Filtration insoluble solid को liquid से separate करती है। जैसे sand और water।
A. मिश्रण के रंगीन components अलग करने के लिए/To separate colored components of a mixture
Step 1
Concept
Chromatography is a separation method based on different movement of components. Separating ink colors is a common example.
Step 2
Why this answer is correct
The correct answer is A. मिश्रण के रंगीन components अलग करने के लिए / To separate colored components of a mixture. Chromatography is a separation method based on different movement of components. Separating ink colors is a common example.
Step 3
Exam Tip
Chromatography components की different movement पर आधारित separation method है। Ink colors को अलग करना common example है।
Fractional distillation is based on boiling point differences. Crude oil mixture is separated into fractions.
Step 2
Why this answer is correct
The correct answer is C. आंशिक आसवन / Fractional distillation. Fractional distillation is based on boiling point differences. Crude oil mixture is separated into fractions.
Step 3
Exam Tip
Fractional distillation boiling point differences पर आधारित है। Crude oil mixture को fractions में अलग किया जाता है।
D. pure substance fixed composition रखता है और mixture variable composition रख सकता है/Pure substance has fixed composition and mixture can have variable composition
Step 1
Concept
A pure substance has definite composition. In a mixture the ratio of components can vary.
Step 2
Why this answer is correct
The correct answer is D. pure substance fixed composition रखता है और mixture variable composition रख सकता है / Pure substance has fixed composition and mixture can have variable composition. A pure substance has definite composition. In a mixture the ratio of components can vary.
Step 3
Exam Tip
Pure substance की composition definite होती है। mixture में components का ratio बदल सकता है।
B. क्योंकि gases chemically fixed ratio में combined नहीं हैं/Because gases are not chemically combined in fixed ratio
Step 1
Concept
Gases in air are present as a physical mixture. Their ratio can vary with place and conditions.
Step 2
Why this answer is correct
The correct answer is B. क्योंकि gases chemically fixed ratio में combined नहीं हैं / Because gases are not chemically combined in fixed ratio. Gases in air are present as a physical mixture. Their ratio can vary with place and conditions.
Step 3
Exam Tip
Air में gases physical mixture के रूप में हैं। उनका ratio स्थान और conditions से बदल सकता है।
B. components और उनके अनुपात पर/On components and their proportion
Step 1
Concept
In a mixture ratio of components can vary. Therefore properties can also change.
Step 2
Why this answer is correct
The correct answer is B. components और उनके अनुपात पर / On components and their proportion. In a mixture ratio of components can vary. Therefore properties can also change.
Step 3
Exam Tip
Mixture में components का ratio बदल सकता है। इसलिए properties भी बदल सकती हैं।
When a compound forms a new substance forms. Therefore its properties can differ from constituent elements.
Step 2
Why this answer is correct
The correct answer is C. अलग हो सकती हैं / Can be different. When a compound forms a new substance forms. Therefore its properties can differ from constituent elements.
Step 3
Exam Tip
Compound बनने पर new substance बनता है। इसलिए इसकी properties constituent elements से अलग हो सकती हैं।
A pure substance often has a sharp melting point. A mixture can show a range.
Step 2
Why this answer is correct
The correct answer is A. अधिक sharp और definite / More sharp and definite. A pure substance often has a sharp melting point. A mixture can show a range.
Step 3
Exam Tip
Pure substance का melting point often sharp होता है। Mixture में range मिल सकती है।
C. वे physical mixture हैं/They are a physical mixture
Step 1
Concept
Salt water is a physical mixture. Components can be separated by evaporation or distillation.
Step 2
Why this answer is correct
The correct answer is C. वे physical mixture हैं / They are a physical mixture. Salt water is a physical mixture. Components can be separated by evaporation or distillation.
Step 3
Exam Tip
Salt water एक physical mixture है। Evaporation या distillation से components अलग किए जा सकते हैं।
D. क्योंकि elements chemical bonds से जुड़े हैं/Because elements are joined by chemical bonds
Step 1
Concept
In a compound components are chemically bonded. Therefore physical separation generally does not work.
Step 2
Why this answer is correct
The correct answer is D. क्योंकि elements chemical bonds से जुड़े हैं / Because elements are joined by chemical bonds. In a compound components are chemically bonded. Therefore physical separation generally does not work.
Step 3
Exam Tip
Compound में components chemically bonded होते हैं। इसलिए physical separation generally काम नहीं करती।
A. components chemically bonded नहीं होते/Components are not chemically bonded
Step 1
Concept
In a mixture components are physically mixed. Therefore methods like filtration and distillation work.
Step 2
Why this answer is correct
The correct answer is A. components chemically bonded नहीं होते / Components are not chemically bonded. In a mixture components are physically mixed. Therefore methods like filtration and distillation work.
Step 3
Exam Tip
Mixture में components physical रूप से मिले होते हैं। इसलिए filtration distillation जैसी methods काम करती हैं।
B. Suspension में बड़े particles settle हो सकते हैं/Large particles can settle in suspension
Step 1
Concept
A true solution remains uniform. In suspension particles are large and can settle.
Step 2
Why this answer is correct
The correct answer is B. Suspension में बड़े particles settle हो सकते हैं / Large particles can settle in suspension. A true solution remains uniform. In suspension particles are large and can settle.
Step 3
Exam Tip
True solution uniform रहता है। Suspension में particles बड़े होते हैं और settle हो सकते हैं।
C. particles naked eye से दिखाई नहीं देते/Particles are not visible by naked eye
Step 1
Concept
Particles of a true solution are very small. Therefore they are not visible by naked eye.
Step 2
Why this answer is correct
The correct answer is C. particles naked eye से दिखाई नहीं देते / Particles are not visible by naked eye. Particles of a true solution are very small. Therefore they are not visible by naked eye.
Step 3
Exam Tip
True solution के particles बहुत छोटे होते हैं। इसलिए वे naked eye से दिखाई नहीं देते।
Particles of suspension are relatively large. Therefore they can settle due to gravity.
Step 2
Why this answer is correct
The correct answer is A. कण settle हो सकते हैं / Particles may settle. Particles of suspension are relatively large. Therefore they can settle due to gravity.
Step 3
Exam Tip
Suspension के particles relatively बड़े होते हैं। इसलिए gravity के कारण settle हो सकते हैं।
A. क्योंकि particles intermediate और stable dispersed होते हैं/Because particles are intermediate and stably dispersed
Step 1
Concept
Colloidal particles are smaller than suspension particles. Therefore they do not settle quickly.
Step 2
Why this answer is correct
The correct answer is A. क्योंकि particles intermediate और stable dispersed होते हैं / Because particles are intermediate and stably dispersed. Colloidal particles are smaller than suspension particles. Therefore they do not settle quickly.
Step 3
Exam Tip
Colloidal particles suspension से छोटे होते हैं। इसलिए वे जल्दी settle नहीं करते।
A. क्योंकि metals या elements variable proportion में mixed हो सकते हैं/Because metals or elements can be mixed in variable proportion
Step 1
Concept
In alloys proportions of components can vary. Therefore they are considered mixtures.
Step 2
Why this answer is correct
The correct answer is A. क्योंकि metals या elements variable proportion में mixed हो सकते हैं / Because metals or elements can be mixed in variable proportion. In alloys proportions of components can vary. Therefore they are considered mixtures.
Step 3
Exam Tip
Alloys में components का proportion vary कर सकता है। इसलिए इन्हें mixtures माना जाता है।
A. pure substances elements compounds और mixtures की पहचान करें/Identify pure substances elements compounds and mixtures
Step 1
Concept
Chemical classification is based on composition. Remember elements compounds mixtures solutions colloids and suspensions with examples.
Step 2
Why this answer is correct
The correct answer is A. pure substances elements compounds और mixtures की पहचान करें / Identify pure substances elements compounds and mixtures. Chemical classification is based on composition. Remember elements compounds mixtures solutions colloids and suspensions with examples.
Step 3
Exam Tip
Chemical classification composition पर आधारित है। Elements compounds mixtures solutions colloids और suspensions को examples से याद रखें।
A. matter को composition के आधार पर pure substances और mixtures में बाँटते हैं/Matter is classified into pure substances and mixtures based on composition
Step 1
Concept
Pure substances have fixed composition and mixtures can have variable composition. Classification becomes easy through examples.
Step 2
Why this answer is correct
The correct answer is A. matter को composition के आधार पर pure substances और mixtures में बाँटते हैं / Matter is classified into pure substances and mixtures based on composition. Pure substances have fixed composition and mixtures can have variable composition. Classification becomes easy through examples.
Step 3
Exam Tip
Pure substances की composition fixed होती है और mixtures की composition variable हो सकती है। Examples से classification आसान होती है।
