Explain how a plant is adapted for photosynthesis

Calculate the molality for each of the following solutions. Then, calculate the freezing-point depression ΔTF = iKFcm produced b

zlopas [31]

Answer:

a) Cm= 3.9 m ; ΔTf= 14.51 ºC

b) Cm= 0.21 m ; ΔTf= 0.79ºC

Explanation:

In order to solve the problems, we have to remember that the molality (m) of a solution is equal to moles of solute in 1 kg of solvent.

m= mol solute/kg solvent

a) In this case we have molarity, which is moles of solute in 1 liter of solution. We have to know how many kg of solvent (water) we have in 1 L of solution.

3.2 M NaCl= 3.2 mol NaCl/ 1 L solution

1 L solution= 1000 ml solution x 1.00 g/ml= 1000 g

A solution is composed by solute (NaCl) + solvent, so:

1000 g solution = g NaCl + g solvent

g NaCl= 3.2 mol NaCl x 58.44 g/mol= 187 g NaCl

g solvent= 1000 g - 187 g NaCl= 813 g= 0.813 kg

Cm= 3.2 g NaCl/0.813 kg solvent= 3.9 m

NaCl is an electrolyte and it dissociates in water in two ions: Na⁺ anc Cl⁻, si the van't Hoff factor (i) is 2.

ΔTf= i x KF x Cm= 2 x 1.86ºC/m x 3.9 m= 14.51ºC

b) In this case we have 24 g of solute in 1.5 L of solvent. We have to convert the liters of solvent to kg, and to convert the mass of solute to mol by using the molecular weight of KCl (74.55 g/mol):

24 g KCl x 1 mol KCl/74.55 g= 0.32 mol

1.5 L solvent= 1500 g solvent x 1.00 g/ml= 1500 g = 1.5 kg

Cm= 0.32 g KCl/1.5 kg solvent= 0.21 m

KCl is an electrolyte and when it dissolves in water, it dissociates in 2 ions: K⁺ and Cl⁻. For this, van't Hoff factor (i) is equal to 2.

ΔTf= i x KF x Cm= 2 x 1.86ºC x 0.21 m= 0.79ºC

7 0

3 years ago

Butane is a common fuel used in cigarette lighters and camping stoves. Normally supplied in metal containers under pressure, the

klasskru [66]

Pressure of Butane in the container at 135°C = 1.07 atm

Given:

The H°vap of butane is 24.3 kJ/mol.

starting out at 25 °C

Temperature at the end: 135 °C

2.3 atm of pressure

To Find:

The container's pressure

The perpendicular force per unit area, also known as the stress at a point within a confined fluid, is known as pressure in the physical sciences.

Equation of Clausius-Clapeyron

P2 = 1.07 atm and ln (P2/2.3 atm)

= - 24.3*110/8.31

The pressure in the container at 135°C (ΔH°vap ) is 1.07 atm

Learn more about Pressure here:

brainly.com/question/25736513

#SPJ4

6 0

1 year ago

Why electronegative decrease going down the periodic table

liraira [26]

Moving down in a group, the electronegativity decreases due to an increase in the distance between the nucleus and the valence electron shell, thereby decreasing the attraction, making the atom have less of an attraction for electrons or protons.

5 0

3 years ago

A certain object has a volume of 25.0 ml and a mass of 100 g. what is the density of the object

Tpy6a [65]

Density= mass/volume

= 100/25
density = 4g/ml

8 0

3 years ago

The s orbitals are said to be non directional what does it mean

ser-zykov [4K]

s - orbitals have a spherical symmetry and the probability of finding an electron in an s orbital is equal for equal distance in x, y or z direction. i mean the probability of lets say an electron found at a distance 10 units from nuclues, its value will be same for x, y and z when u go 10 units distnace from nucleus in these directions. then the value at 5 units would be some value which also would be same for x,y and z.

Easier explanation is that if u place a ball, can u tell towards which axis it is oriented? no, its equally in all directions. So, non- directional.

However, if you have p- orbitals like dumb bells, a dumb bell can be oriented in three different directions, either x or y or z. see the pics.

3 0

3 years ago