DATA PROCESSING ANSWERS

DATA PROCESSING(obj and essay) 10:00am-1:00pm

DATA PROCESSING:
1-10: DEEBDCCCAA
11-20: BBBAAADEAB
21-30: EDCDADBAEA
31-40: ABCBDADBDB
41-50: DBBEEBDCBA
51-60: AADBCACCDB
DATA PROCESSING


(3ai)
Relational database is a digital database whose organization is based on the relational model of data, as proposed by E. F. Codd in 1970.
(3aii)
-Tables
-forms
-queries
(3aiii)
A program file refers to sets of instructions that are put together to build up the application you will be using. Several files are linked between each other to see the application that pops in your screen.
A data file is basically the application's feeding as it provides what is needed for your program to work and convert single pieces of data on understandable information.
(3bi)
Two way, real-time transmission of audio and video signals between specialized devices or computers at two or more locations via satellite (wireless) over a network such as a LAN or
internet.
(3bii)
1. No time constraint:
2. Dramatic travel saving:
3. Easy communication:
4. Increased productivity:


(5)
-Systematic gathering
-Recording
-Analyzing of data
-Collection of data
-Decision making
-Systematic gathering: Is d collection of data frm various sources to gather common knowledge of the people/customers
-Recording: Is the documentation of the data and
-Analyzing of data is when the idea,knowledge dat are collected frm random people are worked on by the research agents
-Collection of data: Is when the research agent use various methods to bring various ideas together from several customers

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-Decision making: Is when the data are collected and analysed & are considered for usage

(9a)
-He decides the demand of the product at that time
-He helps to make arrangement for storage facilities
-He helps to fix the price for the price for the agricultural product
-He helps to look at the quality and quantity of agricultural product to be marketed
-He helps to grade the agricultural product
(9b)
-Facilitator helps to decide where there is the demand for the processed food
-He also helps in fixing the good price for the product
-He decides on how to store the product in the case of excess
-He will decide the quality of the product
-He helps in grading of the product

VERIFIED NECO 2016 CHEMISTRY PRACTICAL QUESTIONS AND ANSWERS

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VERIFIED NECO 2016 CHEMISTRY PRACTICAL QUESTIONS AND ANSWERS

Tuesday 31st may 2016
CHEMISTRY PRACTICAL 10:00am-12:00pm
+++++++++++++++++++++++++++++++++++

1)
volume of pipette used =25.0cm^3

indicator used =methyl orange

burette reading|rough| 21.50|0.00|21.50|

final burette readings (cm^3)|1st|21.20| 0.00. 21.20|

initial burette reading(cm^3)|2nd|31.20|10.00| 21.20|

volume of a used (cm^3)|3rd|41.20|20.00|21.20|

average volume of a used =(21.20+21.20+21.20)cm^3/3
=63.60cm^3/3
=21.20cm^3

equation of the reaction
H2SO4(aq) + 2NaoH(aq)+2H2O(s)
nA=1,nB=2
A=4.90gldm^3 H2SO4
molar mass H2SO4
=(1*2)+32+(16*4)
=2+32+64
=98gmol^-1

molar conc A=mass con A/molar mass A
=4.90gldm^3/98glmol
=0.05moldm^3

CAVA/CBVB=nA/nB
0.05moldm^3*21.20cm^3/CB*25.0cm^3=1/2
0.05moldm^3*21.20*2=CB*25.0
CB=0.05molldm^3*21.20*2/25.0
CB=0.0848moldm^3
in mass conc B =Molar B*MolarBmass
B=NaoH
=23+16+1
=40gmol-^3

mass conc B =0.0848moldm^3 * 40gmol

mass con B = 3.392gldm^3
% mass of impusx 100%/total mass of implusty

mass of implus =(4.0-3.392)gldm^3
=0.608gldm^3

%impurity =0.608gldm^3*100%/4.0gldm^3
=15.2%

3ai)
Drawing lebel
-lid
-sticky tape(to hold paper)
-choroatographic paper
-gas jar
-applied spot of solute mixture
-ion

3aii)
principle of dillution, C1 V1=C2 V2
2.0molldm^3*40

3bi)
ethanol—->ethanoic (acid)—->trioxonotrate(v) (acid)

3bii)
indicators are used to determine the end point of the reaction and to test the acidity or alkalinity of a solution

2ai)
Observation: The salt sample dissolves completely
Inference: C is a mixture of soluble salts

(2aii)
Observation: White precipitate insoluble in excess NaOH(aq)
Inference: Ca^2+ present

(2aiii)
Observation: No visible reaction
Inference: Ca^2+ is present

(2aiv)
Observation: Brownish fume is produced
Inference: NO2(g) form, NO3^- present

(2av)
Observation: Formation of brown gas which forms a ring junction with FeSO4
Inference: NO2 form, NO3^- confirmed

(2bi)
Observation: D dissolves completely. Formation of dirty green precipitate insoluble in excess NaOH(aq)
Inference: D is soluble in salt, Fe^2+ present

(2bii)
Observation: Formation of a white precipitate.precipitate remains insoluble in HCl(aq)
Inference: SO3^2-,CO3^2-,SO4^2- present,SO4^2- confirmed 

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