This hydrated iron oxide is rust. Question 2: Write the balanced equation for the following chemical reactions. William I, the Prussian king, was proclaimed German Emperor in January 1871, at Versailles. Hence, it is the best conductor. Question 6: Why does the colour of copper sulphate solution change when an iron nail is dipped in it? Why does the cord of an electric heater not glow while the heating element does? Why does the colour of copper sulphate solution change when an iron nail is dipped in it? Calcium hydroxide dissolves in water to form its solution called lime water.
Endothermic reactions require heat energy to form products. Such an average tells us nothing about whether the number of children dying before the age of one are mostly boys or girls. Answer d The given reaction is an example of a displacement reaction. In beakers A and B, exothermic process has occurred. However, it would be wrong to say that per capita income is not a useful criterion at all.
Answer A reaction which has an equal number of atoms of all the elements on both sides of the chemical equation is called a balanced chemical equation. The comparative concentration of the water gives a signal to the brain which then takes the required corrective action of either reabsorbing water or releasing it. The equation of the reaction involved on heating copper is given below. Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal? Why should a magnesium ribbon be cleaned before it is burnt in air? Other possibilities fifty years from now, could include ethanol, bio-diesel, nuclear energy and a better utilisation of wind energy, especially with the imminent danger of oil resources running out. This implies that iron is a better conductor than mercury. Small intestine is especially adapted for absorbing the digested food. However, on facing opposition from the aristocracy and military, and on losing its mass support base, it was forced to disband.
Therefore, current can flow more easily through thick wire than a thin wire. Why should chemical equations be balanced? But the resistance of cord which is usually of copper or aluminum is very law so it does not glow. We give you 1 full hour of trial class to clear your doubts. Thick wire means more area of cross-section and lower the resistance of wire. Question 3: Through a focus on any two countries, explain how nations developed over the nineteenth century. Collecting and recording the different forms of folk culture was important for building a national consciousness. The resistances are connected in series.
Soln: Iron articles are painted to prevent them from rusting. Answer: The main criterion used by the World Bank in classifying different countries is the per capita income or average income of a person in a country. Define the unit of current. Therefore, it does not conduct electricity. The questions and answers which are given in provide a thorough understanding of all concepts and topics. The different Slavic communities in the Balkans began to strive for independent rule. What is the difference between displacement and double displacement reactions? During the 1830s, he strived to put together a coherent programme for such a unitary Italian Republic.
The following circuit diagram shows three resistors of resistances 5Ω , 8Ω and 12Ω respectively connected in series and a battery of potential 6 V and a plug key which is closed means the current is flowing in the circuit. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be exposed into air. If you carry on with such a lifestyle then it is going to be harmful to your health in a long run. To measure the potential difference across the resistor it should be connected in parallel, as shown in the following figure. This will help you understand the problem discussed in a question and then come with an appropriate answer. The reaction is as follows: Although aqueous solutions of glucose and alcohol contain hydrogen, these cannot dissociate in water to form hydrogen ions. Answer: The present sources of energy that are used by the people of India are electricity, coal, crude oil, cowdung and solar energy.
These ions conduct electricity in the solution resulting in the glowing of the bulb. Now a drop of basic solution is mixed with a drop of each of the remaining two solutions separately and then the nature of the drops of the mixtures is checked. I have some suggestions that you could follow for your own well being. Q12 : C-reactive protein a when produced more in the body causes heart failure. The law of conservation of mass states that mass can neither be created nor destroyed. If the colour of red litmus turns blue, then the second solution is neutral and if there is no change in colour, then the second solution is acidic. Many bright students miss golden opportunities because of lack of guidance and are not able to perform optimally in spite of deep interest and willingness to work hard.
For example, the infant mortality rate of a country does not differentiate between the male and female infants born in that country. One of the most important events in the universe is a chemical reaction. Question 13 Redraw the circuit of question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure potential difference across the 12Ω resistor. Water contains two parts of hydrogen and one part oxygen. When the revolutionary uprisings of 1831 and 1848 failed to unite Italy, the responsibility to establish a unified Italy fell upon this Italian state.
The symbols of new Britain—the British flag, the national anthem and the English language were widely popularised, while the distinctive identities of the other joining states were systematically suppressed. Video Solution Answer: Two important uses of washing soda and baking soda are as follows: 1 Washing soda: a It is used in glass, soap, and paper industries. A drop of the solution in A is put on the red litmus paper. Would writing the equations get you extra marks or would you just be wasting your time? When one of such compound formed is in solid form that is insoluble in aqua then it settles down at the bottom of the container. He formulated the Civil Code of 1804, also known as the Napoleonic Code. Unification with the help of the army: After the failure of the revolutions, the process of German and Italian unification was continued by the aristocracy and the army.
This solid is known as the precipitate and the respective reaction is termed as the precipitation reaction. Shake it and pass the gas produced into a soap solution. The resistance of a conductor depends on following factors. Its chemical formula is CaO. Your school choice, subjects and future path all depends on these exams. This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen.