8/20/2019 worksheet osmosis and diffusion
1/1
Self-assessment questions
How substances get in and out of cells
1. Containers X and Y each hold one litre of air. X also
contains 0.4g of a gas and Y contains 0.6 g of the samegas. The two
containers are connected together as shown in the diagram.
(a !hich wa" will the gas diffuse#
($ %fter a long &eriod of time' what will $e the
concentration of the gas (in grams &er litre in
eachcontainer#
. The diagram re&resents (not to scale molecules of a salt
dissol)ed in the
$ottom la"er of water in a $ea*er. +a*e two similar
diagrams to show thedistri$ution of salt molecules
(a after a few minutes
($ after se)eral hours.
,. !hen a cell is res&iring aero$icall"' which two gases are
li*el" to $ediffusing in and out of the cell' and in which
direction will the" $e diffusing#
4. !hich one of the following is the $est definition of
osmosis#(a The mo)ement of water from a concentrated solution to a
dilute solution across a &artiall" &ermea$le
mem$rane.
($ The mo)ement of a dissol)ed su$stance from a concentrated
solution to a dilute solution across a &artiall"
&ermea$le mem$rane.
(c The mo)ement of water from a dilute solution to a
concentrated solution across a &artiall" &ermea$le
mem$rane.
(d The u&ta*e of water $" a li)ing cell.!hich of the
statements is an acce&ta$le descri&tion of diffusion#
. The diagram shows a )essel which contains
a concentrated and a dilute solution se&arated $" a
&artiall" &ermea$le mem$rane. raw a
similar diagram to show the liquid le)els after
an hour or two.
!hich statement is correct#(a % concentrated solution has a
high
osmotic &otential (water &otential.
($ % concentrated solution has a lowosmotic &otential (water
&otential.
6. The drawing shows the outline of a human cell.Co&" the
drawing and ma*e two further drawings to show
how the cell would a&&ear if it were to $e immersed for
a
few minutes in a solution with(a a lower osmotic &otential
(water &otential than its
own c"to&lasm($ a higher osmotic &otential (water
&otential than its
own c"to&lasm.
/. % coo* &re&ares a fresh fruit salad $" cutting u&
a )ariet" of fruits and &lacing them in a $owl with la"ers
of
sugar in $etween. %fter two hours the fruit is surrounded $"
s"ru& (concentrated sugar solution.
X Y
0.4g 0.6g
X Y
dilutesolution
concentratedsolution
membrane
8
6
4
2
&lain' as full" as "ou can'
wh" s"ru& (concentrated
sugar solution was &roduced after two hours.
