Rustomjee Cambridge International School & Junior College
1st TERM EXAMINATION (2012- 13)SUBJECT: Chemistry GRADE:VII Div.____
---Question Number 1 2 3 4 5 6 7 8 9 10 Total
Marks Obtained
Q1) Choose the correct alternative:- [10 marks]
1. The diagram shows an atom.
What are the proton number and neutron number of the atom?
2. What is formed when calcium carbonate is heated?
A) calcium and carbon B) calcium and carbon dioxide
C) calcium oxide and carbon D) calcium oxide and carbon dioxide 3. Which formula represents a compound containing three atoms only?
Name:_____________________________________________________Roll No.__________
4. A student carries out an experiment to find how fast 3 cm pieces of magnesium ribbon dissolve in10 cm3 samples of sulfuric acid at different temperatures. Which piece of apparatus does the student not need?
A) balance B) measuring cylinder C) stop-clock D)thermometer 5. Hydrogen and chlorine react as shown.
What is the equation for this reaction? 6.
Which change to an atom occurs when it forms a positive ion?
A) It gains electrons B) It gains protons C) It loses electrons D) It loses protons. 7. What do the nuclei in hydrogen molecules contain?
A) Electrons and protons B) protons and neutrons C) neutrons only D) protons only 8. What is the correct arrangement of electrons in an argon atom (atomic no. 18)
A) 8.8.2 B) 2.8.8 C) 2.8.2.6 D) 8.2.8
9. A molecule of urea contains the following:
1 atom of carbon, C 1 atom of oxygen, O 4 atoms of hydrogen, H 2 atoms of nitrogen, N What is the formula of UREA?
A) CO(NH)2 B) CN2(OH)4 C) CO(NH2)2 D) CH2(NO)2
10. Iron (II) chloride reacts with chlorine to produce iron (III)chloride. What do the roman numerals (I) and (II) show in these iron compounds?
A) The valency of iron B) The iron is in a solid and liquid state. C) Number of atoms of iron in the iron compounds
11. Which of these is used for making glass for window panes?
A) Crooke’s glass B) soft glass C) hard glass D) flint glass 12. Which colour does manganese impart to glass?
A) blue B) green C) yellow D) violet 13. The plant deadly nightshade contains the alkaloid
A) quinine B) morphine C) atropine D) aconite 14. Urethane foam is a
A) monomer B) natural polymer C) thermoplastic D) thermosetting plastic 15. When hydrochloric acid is added to magnesium ribbon, the burning splinter goes off
with a pop sound. Why?
A) Because magnesium chloride is produced B) Because hydrogen is produced C) Because magnesium added to HCl. D) Because chlorine is produced. 16. The diagram shows burning of coal. Which statements about the chemical reaction are
correct?
A) it is a reversible physical change B) it is an irreversible physical change C) it is a irreversible chemical change D) it is a reversible chemical change
18. Heating of chalk powder is an example of,
A) decomposition reaction B) displacement reaction C) double displacement reaction D) synthesis reaction 19. The diagram shows a molecule of water. In the molecule, A) The hydrogen and oxygen share a pair of electrons.
B) The hydrogen gives the oxygen an electron . C) The hydrogen and oxygen share two pairs of electrons. D) The hydrogen gives oxygen two electrons.
20. Which particle is an ion?
number of protons number of neutrons Number of electrons
A) 1 0 1
B) 3 4 3
C) 6 6 6
D) 11 12 10
Q2. A. Write the chemical formulas of the compounds produced from the ions listed
below:- (6 Marks)
PO43- OH- Cl- O
2-Fe2+
Na+
Au3+
B. Name the following compounds: (4 Marks)
1. Ca (NO3)2____________________________________________________________________________________
2. KHSO4_______________________________________________________________________________________
3. Cu3N2________________________________________________________________________________________
C. Classify the following as elements or compounds: (4 Marks)
Ozone alcohol
Mercury silver
Iron Nitrogen
Carbon monoxide Sand
D. Balance and write the word equation for each (6 Marks)
i) K + H2O KOH + H2
Balanced equation-__________________________________________________ Word equation-_____________________________________________________ ii) H2O2 H2O + O2
Balanced equation-__________________________________________________ Word equation-_____________________________________________________ iii) P + O2 P2O5
Balanced equation-__________________________________________________ Word equation-_____________________________________________________
Q3.A. Name the type of chemical reaction taking place here. (6 Marks)
1) 4Fe + 3 O2 → 2 Fe2O3
______________________________________________________________________________
2) Ca(OH)2 + 2HCl→ CaCl2+ 2H2O
______________________________________________________________________________
3) NH4NO2 → N2 + 2H2O
______________________________________________________________________________
4) 2 KI + Cl2→ 2KCl+ I2.
______________________________________________________________________________
5) Mg + 2 HCl→ MgCl2 + H2
_______________________________________________________________________________
6) CuSO4 + 2NaOH → Cu(OH)2 + Na2SO4
___________________________________________________
(Pb2+,S2-,SO
42-, CrO42-, Al3+,N3-,Fe3+, Fe2+,HSO4-,K+)
1. Ferrous nitride-___________________________________________________ 2. AluminiumSulphide - _____________________________________________ 3. Lead bisulphate - _________________________________________________ 4. Potassium chromate-______________________________________________
C. Draw and label the Bohr’s atomic structure of sodium, whose mass number is 23
and atomic number is 11. (4+2 Marks)
Draw its atomic structure and label the nucleus, the orbits, the electrons, protons and neutrons.
Complete the following information about sodium atom. i. Number of protons-______________________
ii. Number of electrons-______________________ iii. Number of neutrons-______________________
D. Complete the orbit diagram of magnesium oxide which is an electrovalent compound. Magnesium- 24
12Mg and oxygen- 168O (4 marks)
Write the chemical formula of the above compound. ______________________________________________
Q4.A.Match the following. (3 marks)
1) Suffering from high blood pressure- a. sulfonamides 2) Suffering from hay fever b. anti inflammatory 3) Suffering from pneumonia c. cardiovascular drugs 4) Undergoing Surgery d. anti inflammatory 5) Having a headache and fever e. antihistamines 6) Complaining of pain and f. analgesics swelling in the joints
Answer: 1-_____, 2-______,3-______, 4-______, 5-_______, 6-________. KEY:
B. What do the following represent in terms of atom, molecule, ion and radicals.
Tick the correct box. (2 marks)
atom molecule ion radical
CO2
3Co CO3
2-Ca2+
C. Soap is used in cleansing dirt. A soap molecule looks like a tadpole.
a. Label the above soap molecule as the water-soluble and fat-soluble group. (1 mark) b. Which part of the soap molecule gets attached to the dirt on the cloth. (½ mark)
______________________________________________________________________
c. What is a detergent? (1 mark)
______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ _____________________________________________________________________
d. The process of splitting fats or oils using alkalis is called_______________. (½ mark)
e. Mention 2 advantages and 2 disadvantages of using synthetic detergents. (4 marks)
Advantages Disadvantages
________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________
D. Reema bought 2 tins of emulsion paint, one for her kitchen and the other for the exterior of her house. The paint suited the kitchen but not the exterior of her house. (3 marks)
i. Why did the paint suit the kitchen?
______________________________________________________________________ ______________________________________________________________________ ii. Why did the paint not suit the exterior of her house?
______________________________________________________________________ ______________________________________________________________________ iii. What type of paint should she buy for the exterior of her house?
______________________________________________________________________ ______________________________________________________________________
Q5.A. The following pictures represent either a physical or a chemical change. Identify them and give reason for your answer. (4 marks)
2)
3)
4)
Change-________________________________________ Reason -________________________________________ _______________________________________________
1)
Change-________________________________________ Reason -________________________________________ _______________________________________________
Change-________________________________________ Reason -________________________________________ _______________________________________________ Change-________________________________________ Reason -________________________________________
B. These are the things made of plastic we use frequently.
i)
a. Name the types of plastic used in making the following: (2 marks)
i- __________________________ ii-___________________________ b. Plastic has brought a revolutionary change in our lifestyle. Mention any 4
characteristics of plastics. (2 marks)
______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________
C. Mr Desai is a contractor. He is involved in different types of construction works. The type of cement he uses is quick, slow and medium setting cement
i. Fill in the table below with the type of cement used by him in various construction
works. (3 marks)
CONSTRUCTION TYPE OF CEMENT
1. Pillers of bridge
2. Road
3. A small house
ii. There are lot of problems associated with cement and its use. Mention how it is
responsible in: (2 marks)
a. Causing flash floods-____________________________________________________ ______________________________________________________________________ b. Causing air pollution-____________________________________________________
_____________________________________________________________________
D. Give reason (2 marks)
i) The chemical symbol of lithium is Li, whereas the symbol of lead is Pb.
______________________________________________________________________ ______________________________________________________________________ ________________________________________________________________________
______________________________________________________________________ ii) The colour of copper carbonate changes from bluish green to black on heating.
______________________________________________________________________ ______________________________________________________________________ ________________________________________________________________________
______________________________________________________________________ **************
