Miracle Learning Centre Chemistry Tuition Question on Particulate Nature of Matter. (O Level Chemistry Tuition/ IP Chemistry Tuition)

1 Zinc nitrate, Zn(NO3)2 produces zinc oxide, oxygen gas and nitrogen dioxide gas when it is decomposed. (a) Write the balanced chemical equation for the reaction. _____________________________________________________________ (b) When nitrogen dioxide is cooled, it forms a yellow liquid and then pale yellow crystals. These crystals are heated and the temperature is measured every minute. The following graph can be drawn.

(i) Describe the arrangement and movement of the molecules in the region C – D. __________________________________________________________ (ii) Name the change that occurs in the region B – C. ________________________________________________________ (d) Nitrogen dioxide, oxygen and water react to form dilute nitric acid. Briefly describe how zinc nitrate crystals could be prepared from dilute nitric acid and zinc oxide. _______________________________________________________________ _______________________________________________________________ Miracle Learning Centre Answer to Chemistry Tuition Question on Particulate Nature of Matter. (O Level Chemistry Tuition/ IP Chemistry Tuition) 1a)2Zn(NO3)2  2ZnO + O2 + 4NO2 1b)The molecules are packed closely together and but are disorderly. The molecules are able to move throughout the liquid. 1c)Melting. 1d)1. Add zinc oxide to the hot acid and stir. 2. Remove the excess zinc oxide by filtering. 3. Heat the solution of zinc nitrate in an evaporating dish to produce a saturated solution and cool. 4. Filter the crystals and dry them by squeezing them between filter paper. Learn from our Chemistry Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Chemistry tuition, Physics tuition, Maths tuition and Science tuition Classes.

Best Chemistry Tuition in Singapore

Miracle Learning Centre Chemistry Tuition Question on Redox Reactions. (O Level / IP Chemistry) 1 (a) A sample of manganese oxide was analysed and it was found that 11.0 g of manganese had combined with 4.8 g of oxygen. Find the empirical formula of the oxide.

(b) The reaction between manganese (IV) oxide and concentrated hydrochloric acid produces chlorine gas. MnO2 + 4 HCl MnCl2 + Cl2 + 2 H2O (i) In terms of changes in oxidation states, state and explain which substance is behaving as an oxidising agent in this reaction. ……………………………………………………………………………..………... …………………………………………………………………………………….. (ii) Explain how aqueous potassium iodide can be used to confirm that manganese (IV) oxide is an oxidising agent. ……………………………………………………………………………..………... …………………………………………………………………………………….. (iii) 50 cm3 of chlorine gas was produced in the reaction at room temperature and pressure. What was the mass of MnO2 used? (iv) The chlorine gas produced is bubbled into a solution of sodium bromide. Write an ionic equation for the reaction and describe the observations that will be made. ……………………………………………………………………………..………... ……………………………………………………………………………..………... ……………………………………………………………………………………..

Miracle Learning Centre Answer to Chemistry Tuition Question on Redox Reactions. (O Level / IP Chemistry) 1 (a) Mass (g) No. of moles Simplest ratio Mn 11.0 0.2 1 O 4.8 0.3 1.5 Empirical formula: Mn2O3

(b) (i) MnO2. The oxidation state of Mn decreases from +4 in MnO2 to +2 in MnCl2. Oxidising agents are reduced during reaction. (ii) KI is a reducing agent. The presence of an oxidizing agent like MnO2 will oxidize KI, causing it to turn from colourless to brown. (iii) No. of moles of Cl2 = (50/1000)/24 = 2.0833 x 10-3 No. of moles of MnO2 = 2.0833 x 10-3 Mass of MnO2= 2.0833 x 10-3 X (55 + 2 x 16) = 0.181g (to 3 s.f.) (iv) Cl2 + 2Br -  Br2 + 2Cl- The colourless solution will turn reddish-brown. Learn from our Chemistry Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Chemistry tuition, Physics tuition, Maths tuition and Science tuition Classes.

Atomic structure

Chemistry tuition classes in Miracle Learning Centre is very useful. If you do not understand chemistry, you must definitely attend the chemistry tuition class at Miracle Learning Centre. Let us learn about atomic structure in this chemistry tuition lesson.

Your chemistry tuition teacher at Miracle Learning Centre will teach you about atomic structure. An atomic consists of three types of particles: proton, electron and neutron. The proton is positively charged and has a similar mass as the neutron. Protons and neutrons are found in the nucleus. The electron is negatively charged and has a mass of 1/1840 of the proton. It is found in the shells outside of the nucleus.

The proton number is the number of protons in the atom. The nucleon number is the number of protons and neutrons in the atom. To find the number of neutrons, we take the nucleon number minus the proton number. The number of protons is equal to the number of electrons in a neutral atom. The positively charged ion has more protons than electrons. The negatively charged ion has more electrons than protons.

The student at Miracle Learning Centre asked, " By looking at the periodic table, how do i tell the electronic configuration of a flourine atom? "

The chemistry tuition teacher at Miracle Learning Centre replied, " An atom has the same number of protons and electrons. Since the proton number of flourine is 9, it should have 9 electrons. The first shell can hold a maximum of 2 electrons. The second shell can hold a maximum of 8 electrons. Hence the electronic configuration of flourine atom is 2,7."

Miracle Learning Centre hope you have understood atomic structure and how it helps you to answer chemistry tuition questions. Do come to Miracle Learning Centre for more chemistry tuition lessons to learn more about atomic structure and chemistry.