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Ymorist [56]
3 years ago
9

(a) The absorbance of mixture at 400 nm was 0.40.

Chemistry
1 answer:
laiz [17]3 years ago
6 0

Answer:

0.1 g/dl

Explanation:

The standard curve is a graph that relates the absorbance at 400 nm with the concentration of haemoglobin in mg/dl. To obtain the concentration from the absorbance value, we enter in the x-axis (absorbance at 400 nm) with the value 0.40 (the line between 0.2 and 0.6), we extrapolate the line to the curve and read the correspondent value on y-axis (concentration in mg/dl): 100 mg/dl.

So, we convert the concentration from mg/dl to g/dl by dividing into 1000:

100 mg/dl x 1 g/1000 mg = 0.1 g/dl

Therefore, the concentration of haemoglobin of the patient is 0.1 g/dl.

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42.9 liters of hydrogen are collected over water at 76.0 °C and has a pressure of 294 kPa. What would the pressure (in kPa) of t
BabaBlast [244]

Answer:

494.1 kPa

Explanation:

Using the combined gas law equation;

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (kPa)

P2 = final pressure (kPa)

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the information provided in this question,

P1 = 294 kPa

P2 = ?

V1 = 42.9 liters

V2 = 22.8 liters

T1 = 76.0°C = 76 + 273 = 349K

T2 = 38.7°C = 38.7 + 273 = 311.7K

294 × 42.9/349 = P2 × 22.8/311.7

12612.6/349 = 22.8 P2/311.7

36.14 = 22.8P2/311.7

Cross multiply

36.14 × 311.7 = 22.8P2

11264.605 = 22.8P2

P2 = 11264.605 ÷ 22.8

P2 = 494.1 kPa

3 0
2 years ago
Which shows the weight of an atom?
sammy [17]

Answer:

The atomic mass

Explanation:

3 0
3 years ago
Salt is the product formed by a reaction in which _______ atoms of an acid are replaced by the atoms of a metal.
UkoKoshka [18]
<span>Salt is the product formed by a reaction in which the hydrogen atoms of an acid are replaced by the atoms of a metal. The salt is formed as a result of the neutralization of the acid by base, that is the metal or positive ion replace the hydrogen ion in the acid. For instance: NaO + H2SO4 = NaSO4 + H2O. In this example, Na [sodium] has replaced the hydrogen in H2SO4, thereby forming the salt NaSO4.</span>
7 0
3 years ago
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Which best describes an element?
Aleonysh [2.5K]

I think the answer is a pure substance

6 0
3 years ago
Which element has the same number of valence electrons as calcium?
kipiarov [429]

Answer:

Barium has the same number of valence electrons as calcium

Explanation:

Valence electrons is the number of electrons of an atom on the outer shell.

Those valence electrons can participate in the formation of a chemical bond (if the outer shell is not closed); in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.

<u>Calcium</u> is an atom, part of group 2, called the alkaline earth metals. The alkaline earth metals have 2 valence electrons.

<u>Sulfur </u>is part of a group 16, called the chalcogens or oxygen family. Those atoms have 6 valence electrons. They can form a bound with atoms of group 2 such as calcium, but do not have the same number of valence electrons.

<u>Potassium</u> is part of group 1, called the alkali metals or lithium family. Those atoms have 1 valence electrons. That means  Potassium do not have the same number of valence electrons like calcium.

<u>Neon</u> is part of group 18, the noble gasses. Those are stable atoms, which means they have 8 valence electrons. They do not have the same number of valence electrons like Calcium.

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This means barium has the same number of valence electrons as Calcium.

8 0
3 years ago
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