Answer:
proposing a hypothesis.
Explanation: Therefore the last step in the scientific method is proposing a hypothesis or obtaining a conclusion.
Answer:
Explanation:
<u>1) First law of thermodynamic (energy balance)</u>
- Heat released by the the hot water (345K ) = Heat absorbedby the cold water (298 K) + Heat absorbed by the calorimeter
<u>2) Energy change of each substance:</u>
Heat released or absorbed = mass × Specific heat × change in temperature
- density of water: you may take 0.997 g/ ml as an average density for the water.
- mass of water: mass = density × volume = 50.0 ml × 0.997 g/ml = 49.9 g
- Specif heat of water: 1 cal / g°C
- Heat released by the hot water:
Heat₁ = 49.9 g × 1 cal / g°C × (345 K - 317 K) = 49.9 g × 1 cal / g°C × (28K)
- Heat absorbed by the cold water:
Heat₂ = 49.9 g × 1 cal / g°C × (317 K - 298 K) = 49.9 g × 1 cal / g°C × (19K)
- Heat absorbed by the calorimeter
Heat₃ = Ccal × (317 K - 298 K) = Ccal × (19K)
<u>4) Balance</u>
49.9 g × 1 cal / g°C × (28 K) = 49.9 g × 1 cal / g°C × (19 K) + Ccal × (19 K)
Ccal = [49.9 g × 1 cal / g°C × (28 K) - 49.9 g × 1 cal / g°C × (19 K) ] / 19K
Ccal = 23.6 cal/ K
- Convert to cal / K to Joule / K
23.6 cal / K × 4.18 J / cal = 98.6 J/K
Which rounded to 2 signficant figures leads to 99 J/k, which is the first choice.
Answer:
See below.
Explanation:
CH3CH2CH2CH2OH is butanol.
The carboxylic acid formed , butyric acid has the formula:
CH3CH2CH2COOH.
Structural formula:
H H H O
| | | ||
H - C - C - C - C - OH
| | |
H H H
M(dextrose) = 50 g.
V(solution) = 1 L.
n(dextrose) = 50 g ÷ 180 g/mol.
n(dextrose) = 0,27 mol.
Osmotic concentration (osmolarity)<span> is a measure of how many </span><span>osmoles of particles of solute</span><span> it contains </span>per liter.
The osmolarity = n(dextrose) ÷ V(solution).
The osmolarity = 0,27 mol ÷ 1 L.
The osmolarity = 0,27 mol/L · 1000 mmol/m.
The osmolarity (dextrose) = 270 mosm/L.
The osmolarity (dextrose monohydrate) = 50 g÷197 g/mol·1000 =254mosm/L
23. The correct answer would be a (AlPO4 + H2O).
This is an example of a neutralization reaction (an acid and a base react to form water and a salt).
24. a, combination reaction. There are two reactants and one product.
