Branliest to correct answer

Which of these solutions has the highest freezing point?

ANEK [815]

Answer: 1.0 M molecular sucrose (C₁₂H₂₂O₁₁).

Explanation:

1) The depression of the freezing point of a solvent when you add a solute is a colligative property.

2) Colligative properties are those physical properties of solutions that depends on the number of solute particles dissolved into the solution.

3) The relation between the number of solute particles and the depresson of the freezing point is proportional: the greater the number of solute particles the greater the freezing point depression.

4) You need to find the solution with the highest freezing point, this is the solution in which the freezing point decreased the least.

5) Then, that is the solution with least number of solute particles.

6) Since all the given solutions have the same molarity (1.0 M), you only have to deal with the possible ionization of the different solutes.

7) NaCl, CaBr₂, AlBr₃, and KCl are ionic compounds, so each unit of them will ionize into two, three, four, and two ions, respectively, while sucrose, being a covalent compound does not dissociate.

Then, 1.0 M solution of sucrose will have less solute particles than the others, and will exhitibit the lowest freezing point depression, meaning that it will have the highest freezing point of the given solutions.

5 0

3 years ago

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Suppose there is 0.63 g of HNO3 per 100 mL of a particular solution. What is the concentration of the HNO3 solution in moles per

Vadim26 [7]

Answer:

There are 0.09996826 moles per liter of the solution.

Explanation:

Molar mass of HNO3: 63.02

Convert grams to moles

0.63 grams/ 63.02= 0.009996826

Convert mL to L and place under moles (mol/L)

100mL=0.1 L

0.009996826/0.1= 0.09996826 mol/L

4 0

3 years ago

Calculate the energy (in J/atom) for vacancy formation in silver, given that the equilibrium number of vacancies at 800 C is 3.6

MAXImum [283]

Answer:

the energy vacancies for formation in silver is $\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

Explanation:

Given that:

the equilibrium number of vacancies at 800 °C

i.e T = 800°C is 3.6 x 10¹⁷ cm3

Atomic weight of sliver = 107.9 g/mol

Density of silver = 9.5 g/cm³

Let's first determine the number of atoms in silver

Let silver be represented by N

SO;

$N = \dfrac{N_A* \rho _{Ag}}{A_{Ag}}$

where ;

$N_A =$ avogadro's number = $6.023*10^{23} \ atoms/mol$

$\rho _{Ag}$ = Density of silver = 9.5 g/cm³

$A_{Ag}$ = Atomic weight of sliver = 107.9 g/mol

$N = \dfrac{(6.023*10^{23} \ atoms/mol)*( 9.5 \ g/cm^3)}{(107.9 \ g/mol)}$

N = 5.30 × 10²⁸ atoms/m³

However;

The equation for equilibrium number of vacancies can be represented by the equation:

$N_v = N \ e^{^{-\dfrac{Q_v}{KT}}$

From above; Considering the natural logarithm on both sides; we have:

$In \ N_v =In N - \dfrac{Q_v}{KT}$

Making $Q_v$ the subject of the formula; we have:

${Q_v = - {KT} In( \dfrac{ \ N_v }{ N})$

where;

K = Boltzmann constant = 8.62 × 10⁻⁵ eV/atom .K

Temperature T = 800 °C = (800+ 273) K = 1073 K

$Q _v =-( 8.62*10^{-5} \ eV/atom.K * 1073 \ K) \ In( \dfrac{3.6*10^{17}}{5.3 0*10^{28}})$

$\mathbf{Q_v = 2.38 \ eV/atom}$

Where;

1 eV = 1.602176565 × 10⁻¹⁹ J

Then

$Q_v = (2.38 \ * 1.602176565 * 10^{-19} ) J/atom }$

$\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

Thus, the energy vacancies for formation in silver is $\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

8 0

4 years ago

How does density relate to the cold and warm air masses?

Amanda [17]

Warmer air is less dense than cold air.As air warm it rises while the cold air sink. Warmer air masses forces the cooler air to move which causes wind. These is illustrated when you open a hot oven the hotter air inside the oven rises into cooler air outside the oven.

3 0

3 years ago

Leah is trying to determine how music affects the growth of plants. She hypothesizes that classical music will cause a plant to

Pani-rosa [81]

Leah's experiment:
A. Takes careful and regular measurements (she measures the growth every day)
B. Has a specific hypothesis and a controlled experiment (the music is the only changing variable, the growth conditions are identical, and this is what she wants to test in her hypothesis)
C. Experimental data that can be recorded and analyzed (measuring the growth of plant fits this)

So the answer must be D, since there is no mention of past research that scientists have found on this topic.

8 0

4 years ago

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