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Biology; Chemistry; Physics: Post your doubts here!

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273
6 A student added 10.0 cm3
of 0.100 mol/dm3
hydrochloric acid to an excess of zinc. The
volume of hydrogen produced was recorded at intervals until no more gas was produced.
This was experiment P.
The experiment was repeated with a different acid solution, again using an excess of zinc.
This was experiment Q.
The graphs of the two experiments are shown on the grid below.
volume of
hydrogen
/ cm3
time/ s
P
Q
Which acid solution would give the graph for experiment Q?
(a) 10 cm3
of 0.050 mol/dm3
hydrochloric acid
(b) 10 cm3
of 0.200 mol/dm3
hydrochloric acid
(c) 20 cm3
of 0.100 mol/dm3
hydrochloric acid
(d) 20 cm3
of 0.200 mol/dm3
hydrochloric acid


i cannot find anything about powder form in this question? :confused:
please view my comment
 
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Pls help ASAP biology mcq
november2006 que 14 paper mcq
June2009 que 13 paper m q
Same question on cardia. Cycle but diff answer :-/ and to 2009 is A and 2006 is B please help
 
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i guess it z :?
i also think the same thing :p
well...this is written in the mark scheme...i got the first 2 points...but what does the third point (bold one) mean?

idea that

both alleles / HbA and HbS, are expressed
;


both alleles make two different forms of haemoglobin

;
if dominant / recessive, then only one form of
haemoglobin in heterozygous people

;
three phenotypes (not two) / sickle cell trait is a different
phenotype from normal and sickle cell anemia

;
 
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What is Antimatter? :p
In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. But this is nt in our syllabus :/
 
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Please explaiin nitrogen cycle in short :D ?
800px-Nitrogen_Cycle.svg.png
t
THERE U GO, the siplest drawing
 
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In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. But this is nt in our syllabus :/
I kno it's
In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. But this is nt in our syllabus :/
not in our syllabus..jus kidding
 
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Q) phagocytes and lymphocytes are the same in size then why cant lymphocytes squeeze out of capillary walls in tissue fluid ?
circulating phagocytes produce surface glycoprotein receptors that increase their ability to adhere to the inner surface of capillary walls, enabling them to squeeze out of the capillary and be attracted to the site of infection.
 
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