A. What is the solubility in grams for HCl at 40℃?

Though a needle is several times as dense as water, a small needle can be made to float on the surface of water if placed carefu

viva [34]

The water is more dense than the needle so it can withstand the weight. It is the contraction of the water falling faster than the others forming a drop pattern or the water getting smaller so the top looked smaller.

3 0

2 years ago

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You were instructed to add 1.0 mL out of 4.0 mL of an undiluted sample to 99 mL of sterile diluent. Instead, you add the entire

finlep [7]

Answer:

A.) Intended dilution factor : 0.01

B.) Actual dilution factor: 0.039

Explanation:

Dilution factor(DF) is ratio of the volume of the undiluted sample to total volume of diluted solution

A.) What was your intended dilution factor

This would be the the addition 1.0ml from 4.0ml to 99ml of sterile

Volume of sterile diluent = 99ml

Volume of Undiluted sample = 1.0ml

Total volume of diluted solution = 99ml + 1m = 100ml

Dilution factor = Volume of undiluted sample ÷ Total volume of diluted solution

Dilution factor = 1:100

= 1ml ÷ 100ml

= 0.01

B.) What was your actual dilution factor?

This would be the entire addition of 4.0ml to 99ml sterile diluent

Volume of sterile diluent = 99ml

Volume of Undiluted sample = 4.0ml

Total volume of diluted solution = 99ml + 4.0ml = 103ml

Dilution factor = Volume of undiluted sample ÷ Total volume of diluted solution

Dilution factor

= 4:103

= 4ml ÷ 103ml

= 0.039

8 0

2 years ago

How many grams are in 4.0 moles of lithium

Fittoniya [83]

Answer:

The correct answer is 27.764 grams.

Explanation:

A standard scientific unit for determining the large quantities of very small entities like molecules, atoms, or other specific particles is termed as a mole. The molecular weight of lithium is 6.941 grams per mole. Thus, one mole of lithium has 6.941 grams.

If, 1 mole of Li has 6.941 grams, then 4 moles of Lithium will have,

= Molecular mass of lithium/1 mole * 4 mole

= 6.941 gram per mole/1 mole * 4 moles.

= 27.764 grams

3 0

2 years ago

9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine

il63 [147K]

Answer:

See explanation

Explanation:

Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.

In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.

Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.

7 0

2 years ago

2.5 piece of lithium is dropped into a 500 g sample of water at 22.1 C.ten temperature of the water increases to 23.5 C. How muc

Dominik [7]

Answer:

2.6 kJ

Explanation:

The formula for the amount of heat (q) absorbed by the water is

q = mCΔT

1. Calculate ΔT

ΔT = 23.5 °C - 22.1 °C = 1.4 °C

2. Calculate q

q₂ = mCΔT = 500 g × 4.184 J·°C⁻¹g⁻¹ × 1.4 °C = 2900 J = 2.9 kJ

3 0

3 years ago