ALEKS Chemistry Chapter 2 Questions and Answers Rated A+

ALEKS Chemistry Chapter 2 Questions and Answers Rated A+ Sample A is 100.g of a coarse grey powder with a faint unpleasant smell. 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? mixture 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? mixture Write the chemical symbols for three different atomic cations that all have 5 protons. B+3, B+2, B+5 Write the chemical symbols for three different atomic anions that all have 17 protons. Cl-,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? Mixture 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. Can'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. mixture 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. Mixture 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. Mixture 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. Mixture 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. Pure 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. Can't Decide 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 10.0g. Can't Decide 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 two separate clear layers form in the liquid. When the temperature is raised back to room temperature, the layers disappear. Mixture Sample A is a solid yellow cube with a total mass of 50.0g . The cube is put into a pressure chamber and the pressure raised by pumping in nitrogen gas. At a pressure of an orange liquid is observed seeping from the cube. Liquid continues to seep from the cube as long as the pressure is applied. Can't Decide 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 heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL . Mixture 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 continues to decrease as more crystals form, until at 6.2°C the liquid is entirely solid. Mixture Sample B is 100.g of a coarse grey powder with a faint unpleasant smell. of the powder are put into a very thin tube and heated. The powder begins melting at 66.2°C. The temperature stays constant as the powder slowly melts. After the last of the powder melts, the temperature starts to rise again, eventually reaching 76.0°C. Pure Substance 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 volume of each subsample is measured. The volume of the first is 48.2cm3 and the volume of the second is 58.1cm3. When the experiment is repeated with a new 50.0g. sample, the volume of the two 25.0g subsamples is 52.2cm3 and 50.8cm3. Mixture Sample B is 100.g of a coarse grey powder with a faint unpleasant smell. 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. Mixture Sample A 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. Additionally, there is a dark green ring surrounding the inner stain. Mixture Sample B is 100.mL of a clear liquid. The liquid is heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL. The density of the liquid that boiled off turns out to be 1.05/gmL. Can't Decide Sample A is 100.mLof a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL. The liquid is then heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL. Mixture 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 heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL. Mixture Element 1 is a faintly yellow gas. 100cm3 of the gas are compressed to a new volume of 10cm3 . When the compressed gas is allowed to leak out through a small hole, it becomes very cold. Nonmetal Element 2 is a shiny silvery-gray solid. A ×5cm5cm square of it, only 1mm thick, is pressed into a dish-shaped mold under high pressure. When the sample is removed, it has become lighter in color and now has the shape of the mold. Metal Element 3 is a hard dark-red solid. A ×5cm5cm square of it, only 1mm thick, is flexed slightly by hand. The sheet snaps in half. Nonmetal Element 1 is a moderately soft silvery-gray solid. A small ×2cm×2cm2cm cube of it is put into a hydraulic press and squeezed until it is half as thick. When the sample is inspected, the surface has become lighter, and it has the shape of a smooth disk. Metal Element 2 is a shiny silvery-gray solid. Wires are fastened to each side of a 2cm slab of it, and an ordinary household 9V battery is hooked up so that it can feed electricity through the slab to an LED. But the LED stays dark. Nonmetal Element 3 is a hard silvery-gray solid. Wires are fastened to each side of a 2cm slab of it, and an ordinary household 9V battery is hooked up so that it can feed electricity through the slab to an LED. The LED glows brightly. Metal Element 1 is a moderately soft silvery-gray solid. Two thin rods are manufactured of the element and placed about 1cm from each other. When a high voltage is applied across the pair of rods, a spark can be seen jumping from one rod to another. Metal Element 2 is a moderately soft silvery-gray solid. A 10.g cube of it is set on a hot plate. After 10 minutes, the temperature of the top of the cube has risen by less than 1°C Nonmetal Element 3 is a hard silvery-gray solid. A small 10.g cube of it is tapped lightly with a small hammer. This causes one of the corners of the cube to be dented in. Metal NaCl Na+ Cl- V3(PO4)2 V2+ PO^-3 4 NiSO4 Ni+2 SO^-2 4 CoS Co 2+ S 2- MnI4 Mn +4 I- VCO3 V 2+ CO^-2 3 NH4F NH ^+ 4 F - MnCO3 Mn 2+ CO^-2 3 (NH4)2O NH^+ 4 O 2- VSO4 V 2+ SO ^2- 4 Mn(SO4)2 Mn 4+ SO^-2 4 Cr(NO3)3 Cr 3+ NO^- 3 KH2PO3 potassium dihydrogen phosphite CaHPO3 calcium hydrogen phosphite Mg(HCO3)2 magnesium hydrogen carbonate NaHCO3 sodium hydrogen carbonate NaHSO3 sodium hydrogen sulfite Mg(H2PO3)2 magnesium dihydrogen phosphite