1. what is the maximum volume of a 0.788 m cacl₂ solution that can be prepared using 85.3 g cacl₂?\na. 1.00…

1. what is the maximum volume of a 0.788 m cacl₂ solution that can be prepared using 85.3 g cacl₂?\na. 1.00 l\nb. 0.769 l\nc. 0.975 l\nd. 67.2 l\n\n2. how many lone pairs of electrons are present but not shown in the molecule below?\nch₃ - ch₂ - c - nh₂\na. 0\nb. 1\nc. 2\nd. 3\ne. 4\n\n3. what is the molarity of a 11.5% (w/v) glucose (c₆h₁₂o₆, molar mass 180.16 g/mol) solution?\na. 0.0638 m\nb. 0.638 m\nc. 1.15 m\nd. 1.76 m\n\n4. which element is most likely to be a good conductor of electricity?\na. ar\nb. n\nc. f\nd. ni\ne. o\n\n5. which element is chemically similar to lithium?\na. sulfur\nb. magnesium\nc. iron\nd. lanthanum\ne. potassium

1. what is the maximum volume of a 0.788 m cacl₂ solution that can be prepared using 85.3 g cacl₂?\na. 1.00 l\nb. 0.769 l\nc. 0.975 l\nd. 67.2 l\n\n2. how many lone pairs of electrons are present but not shown in the molecule below?\nch₃ - ch₂ - c - nh₂\na. 0\nb. 1\nc. 2\nd. 3\ne. 4\n\n3. what is the molarity of a 11.5% (w/v) glucose (c₆h₁₂o₆, molar mass 180.16 g/mol) solution?\na. 0.0638 m\nb. 0.638 m\nc. 1.15 m\nd. 1.76 m\n\n4. which element is most likely to be a good conductor of electricity?\na. ar\nb. n\nc. f\nd. ni\ne. o\n\n5. which element is chemically similar to lithium?\na. sulfur\nb. magnesium\nc. iron\nd. lanthanum\ne. potassium

Answer

Explanation:

Step1: Calculate moles of CaCl₂

The molar mass of CaCl₂ is (M = 40.08+2\times35.45= 110.98\ g/mol). The number of moles (n=\frac{m}{M}), where (m = 85.3\ g). So (n=\frac{85.3\ g}{110.98\ g/mol}\approx0.769\ mol).

Step2: Calculate volume of solution

Using the formula (M=\frac{n}{V}), where (M = 0.788\ M) and (n = 0.769\ mol). Rearranging for (V), we get (V=\frac{n}{M}=\frac{0.769\ mol}{0.788\ mol/L}\approx0.975\ L).

Step3: Analyze lone - pairs in (CH_3CH_2CONH_2)

The oxygen in the carbonyl group has 2 lone - pairs and the nitrogen has 1 lone - pair. So in total, there are 3 lone - pairs not shown explicitly.

Step4: Calculate molarity of glucose solution

A (11.5%\ (w/v)) glucose solution means (11.5\ g) of glucose in (100\ mL) of solution. The number of moles of glucose (n=\frac{m}{M}), with (m = 11.5\ g) and (M = 180.16\ g/mol), so (n=\frac{11.5\ g}{180.16\ g/mol}\approx0.0638\ mol). The volume (V = 100\ mL=0.1\ L). Molarity (M=\frac{n}{V}=\frac{0.0638\ mol}{0.1\ L}=0.638\ M).

Step5: Identify good conductor of electricity

Metals are good conductors of electricity. Among the options, Ni (nickel) is a metal, while Ar, N, F, and O are non - metals.

Step6: Identify element chemically similar to lithium

Elements in the same group of the periodic table have similar chemical properties. Lithium (Li) is in Group 1, and potassium (K) is also in Group 1.

Answer:

  1. C. (0.975\ L)
  2. D. 3
  3. B. (0.638\ M)
  4. D. Ni
  5. E. potassium