Chemistry ALEKS Chapter 2
Sample A is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.mg of the powder are put into
a very thin tube and heated. The powder begins melting at 66.2°C. The temperature
continues to rise as the powder slowly melts, and the last of the powder becomes liquid
at 76.0°C.
Is sample A made from a pure substance or a mixture? - answermixture
Sample B is a solid yellow cube with a total mass of
50.0g
. The cube is ground to a fine orange powder and added to a 500mL beaker full of
water. The beaker is stirred vigorously. Some of orange powder settles to the bottom of
the beaker, and some rises to the top and floats on the water. When the powder at both
the bottom and the top of the beaker is filtered out, dried, and weighed, the total mass is
measured to be 50.1g.
Is sample B made from a pure substance or a mixture? - answermixture
Write the chemical symbols for three different atomic cations that all have
5
protons. - answerB+3, B+2, B+5
Write the chemical symbols for three different atomic anions that all have
17
protons. - answerCl-,Cl-4, Cl-2
Sample A is a solid yellow cube with a total mass of
50.0g
. The cube is put into a beaker filled with 250.mL of water. The cube collapses into a
small pile of orange powder at the bottom of the beaker. When this powder is filtered
out, dried and weighed, it has a total mass of 29.9g. If the experiment is repeated with
500.mL of water, the powder that's left over has a mass of 30.0g.
Pure substance or mixture? - answerMixture
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder are dissolved
in ethanol. 0.5mg of the resulting black solution is carefully dropped onto a thick sheet
, of paper laid flat in a tray. After 30 minutes the initial round black stain has spread out
and faded in color to a deep purple. - answerCan't decide
Sample A is a solid yellow cube with a total mass of
50.0g
. The cube is divided into two smaller 25.0g subsamples, and the minimum volume of
water needed to dissolve each subsample is measured. The first subsample just barely
dissolved in 101.mL of water, the second in 92.mL. When the experiment is repeated
with a new 50.0g. sample, the minimum volume of water required to dissolve the two
subsamples is 89.mL and 93.mL. - answermixture
Sample B is
100.mL
of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL.
The liquid is then cooled in the refrigerator. At 10.0°C crystals begin to appear until the
liquid is about half crystal, half liquid. After 30 minutes, no more crystals appear, even
though the temperature is lowered to 6.3°C. - answerMixture
Sample A is
100.mL
of a clear liquid. The liquid is heated in a flask until it boils, which starts to happen at
66.2°C. As the liquid boils, the temperature continues to rise, until the last of the liquid
boils away at 76.0°C. - answerMixture
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder is put into a
funnel lined with a sheet of thick paper. Distilled water is poured slowly over the powder.
Most of the powder disappears, but of a gritty black sand-like material is left on the
surface of the paper. Pouring more water over the black material doesn't change how
much of it there is. - answerMixture
Sample A is
100.mL
of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL.
The liquid is then cooled in the refrigerator. At 10.0°C crystals begin to appear. The
temperature of the liquid remains at 10.0°C until all the liquid has crystallized. After all
the liquid is frozen, the temperature starts to fall again, eventually reaching 6.2°C. -
answerPure Substance
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder is put into a
funnel lined with a sheet of thick paper. Distilled water is poured slowly over the powder.
All of the powder disappears, and the water under the funnel turns a deep purple. -
answerCan't Decide
Sample A is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.mg of the powder are put into
a very thin tube and heated. The powder begins melting at 66.2°C. The temperature
continues to rise as the powder slowly melts, and the last of the powder becomes liquid
at 76.0°C.
Is sample A made from a pure substance or a mixture? - answermixture
Sample B is a solid yellow cube with a total mass of
50.0g
. The cube is ground to a fine orange powder and added to a 500mL beaker full of
water. The beaker is stirred vigorously. Some of orange powder settles to the bottom of
the beaker, and some rises to the top and floats on the water. When the powder at both
the bottom and the top of the beaker is filtered out, dried, and weighed, the total mass is
measured to be 50.1g.
Is sample B made from a pure substance or a mixture? - answermixture
Write the chemical symbols for three different atomic cations that all have
5
protons. - answerB+3, B+2, B+5
Write the chemical symbols for three different atomic anions that all have
17
protons. - answerCl-,Cl-4, Cl-2
Sample A is a solid yellow cube with a total mass of
50.0g
. The cube is put into a beaker filled with 250.mL of water. The cube collapses into a
small pile of orange powder at the bottom of the beaker. When this powder is filtered
out, dried and weighed, it has a total mass of 29.9g. If the experiment is repeated with
500.mL of water, the powder that's left over has a mass of 30.0g.
Pure substance or mixture? - answerMixture
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder are dissolved
in ethanol. 0.5mg of the resulting black solution is carefully dropped onto a thick sheet
, of paper laid flat in a tray. After 30 minutes the initial round black stain has spread out
and faded in color to a deep purple. - answerCan't decide
Sample A is a solid yellow cube with a total mass of
50.0g
. The cube is divided into two smaller 25.0g subsamples, and the minimum volume of
water needed to dissolve each subsample is measured. The first subsample just barely
dissolved in 101.mL of water, the second in 92.mL. When the experiment is repeated
with a new 50.0g. sample, the minimum volume of water required to dissolve the two
subsamples is 89.mL and 93.mL. - answermixture
Sample B is
100.mL
of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL.
The liquid is then cooled in the refrigerator. At 10.0°C crystals begin to appear until the
liquid is about half crystal, half liquid. After 30 minutes, no more crystals appear, even
though the temperature is lowered to 6.3°C. - answerMixture
Sample A is
100.mL
of a clear liquid. The liquid is heated in a flask until it boils, which starts to happen at
66.2°C. As the liquid boils, the temperature continues to rise, until the last of the liquid
boils away at 76.0°C. - answerMixture
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder is put into a
funnel lined with a sheet of thick paper. Distilled water is poured slowly over the powder.
Most of the powder disappears, but of a gritty black sand-like material is left on the
surface of the paper. Pouring more water over the black material doesn't change how
much of it there is. - answerMixture
Sample A is
100.mL
of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL.
The liquid is then cooled in the refrigerator. At 10.0°C crystals begin to appear. The
temperature of the liquid remains at 10.0°C until all the liquid has crystallized. After all
the liquid is frozen, the temperature starts to fall again, eventually reaching 6.2°C. -
answerPure Substance
Sample B is
100.g
of a coarse grey powder with a faint unpleasant smell. 15.g of the powder is put into a
funnel lined with a sheet of thick paper. Distilled water is poured slowly over the powder.
All of the powder disappears, and the water under the funnel turns a deep purple. -
answerCan't Decide
