When performing your experiment, you add your first drop of oleic acid/benzene solution, and a lens forms immediately. what is w

Answer:

B, D

Explanation:

We need to recognize that the ice will rise in temperature from -6.5 ºC to 0 ºC for it to change into water.

Let's define q₁ as the heat needed to warm the ice to 0ºC, and q₂ as the heat for the transition from solid to liquid.

The calculation for q₁ is as follows:

q₁ = s x m x ΔT, where s represents the specific heat of ice (2.09 J/gºC), m is the mass, and ΔT is the temperature difference.

For q₂, the enthalpy of fusion is computed as:

q₂ = C x ΔT

with C indicating the specific heat for the phase transition, denoted as AH in kJ/mol.

All necessary data for computing q₁, q₂, and the total heat change (q₁ + q₂) is provided.

q₁ = 25.0 g x (2.09 J/gºC) x (0 - (-6.5 ºC))

q₁ = 339.6 J = 0.339 kJ

q₂ = (25 g/18 g/mol) x 6.02 kJ/mol = 1.39 x 6.02 kJ = 8.36 kJ

Combining these values gives us qtotal = 0.339 kJ + 8.36 kJ = 8.70 kJ.

Now we can answer the question:

(a) False, AH refers to the heat capacity during melting.

(b) True, as we concluded earlier.

(c) False, there’s only one phase transition from solid (ice) to liquid.

(d) True based on our calculations above.

(e) False, according to our findings.

Answer:

Heat is absorbed.

Answer: The apparent density of ethylene glycol 3350 is calculated as 3350 = 17g/15.6mL= 1.09g/mL

The specific gravity of the mixture is 1.01

Explanation:

Specific gravity refers to the density of a substance compared to that of a reference substance, typically water.

Specific gravity = density of substance/density of water

The density of a substance measures the mass of that substance relative to its volume.

Density = Mass/Volume

The density of water is known to be 1.00 g/mL,  

Apparent density of ethylene glycol 3350 is assessed as mass/volume

the volume of ethylene glycol = total volume of mixture - volume occupied by water

volume of ethylene glycol = 195.6 - 180 = 15.6 mL

Apparent density of ethylene glycol 3350 = 17g/15.6mL= 1.09g/mL

mass of water is computed as  density of water multiplied by volume of water

mass of water = 1.00g/mL * 180mL = 180 g

Total mass of solution = mass of substance plus mass of water = (17 + 180)g = 197g

Density of the mixture = total mass of the mixture divided by its volume

Density of mixture = 197 g / 195.6 mL = 1.01 g/mL

To find the specific gravity of the mixture, use the formula:

specific gravity of mixture = density of mixture divided by density of water

specific gravity of mixture = 1.01g/mL / 1.00g/mL

specific gravity of mixture = 1.01

Given that the value of X is 10, the formula for the unknown hydrate of sodium sulfate becomes NaSO4.10 H2O.

Calculation:

Step 1: Determine the moles of Na2SO4 and H2O.

Moles are calculated by dividing mass by molar mass.

Moles of Na2SO4 are calculated as 1.42 divided by 142, resulting in 0.01 moles.

For H2O: The mass of H2O is 3.22 - 1.42 = 1.8 g.

The moles of H2O are then calculated as 1.8 divided by 18, which gives us 0.1 moles.

Step 2: Find the mole ratio by dividing each mole quantity by the smallest amount (0.01).

This leads to Na2SO4 = 0.01/0.01 = 1.

            H2O = 0.1/0.01 = 10.

Answer:

The answer is 930 grams of platelets.

Explanation:

The amount of blood given is 1.89 pints. To convert this to gallons:

= 1.89/8 = 0.236 gallons

Since 1 gallon is equal to 3.785 liters,

0.236 gallons equals = 0.236 * 3.785 L = 0.89 L

Given that 1 liter of blood contains 1.04 kilograms of platelets, thus, 0.89 L of blood will have = 1.04 * 0.89 = 0.93 kg of platelets.

As 1 kg equals 1000 grams, the amount of platelets in grams translates to:

= 1000 * 0.93 = 930 grams of platelets.