The correct pathway for air entering the human respiratory system is ______

How can you know if evolution has occured within species?

Murrr4er [49]

You can use the HWE (Hardy Weinberg Equilibrium) equations :

p + q = 1

p^2 + 2pq + q^2 = 1

If the allele combinations do not equal one after a while, evolution has occurred.

4 0

3 years ago

Describe how visible spectroscopy could be used to determine the order of a reaction in which a single colorless reactant produc

d1i1m1o1n [39]

Answer:

Explanation:

In a reaction, where, one of the reactant produces a colored product, visible spectroscopy can be used to determined the order of a reaction, the change in concentration of the reactant which forms the colored product is determined by absorbance measurement over time. The data for the concentration and time are plotted on the y and x axis and If we get a straight line it is a zero-order reaction. If instead, a plot of ln[concentration] versus time gives a straight line, it is a first order reaction. However, If 1/concentration versus time gives a straight line, it is a second order reaction kinetics. The other reactants may be changed while keeping this reactant as constant and change on rate of the reaction is observed to see If the other reactant affects the reaction or not.

8 0

4 years ago

An aqueous solution 10 g of an optically pure substance diluted to 500ml with water and placed in a polarimeter tube 20 cm long.

Gennadij [26K]

Explanation:

Formula to calculate specific rotation is as follows.

Specific rotation ( $[\alpha]$ ) = $\frac{\alpha}{c} \times l$

where, $\alpha$ = observed rotation

c = concentration in g/ml

l = path length in dm

It is given that,

$\alpha = -6.16^{o}$

c = $\frac{10 g}{500 ml}$ = 0.02 g/ml

l = 20 cm = 2 dm (as 1 dm = 10 cm)

Therefore, calculate the specific rotation as follows.

Specific rotation ( $[\alpha]$ ) = $\frac{\alpha}{c} \times l$

= $\frac{-6.16^{o}}{0.02 g/ml} \times 2 dm$

= $-616^{o}$

Thus, we can conclude that the specific rotation of this compound is $-616^{o}$ .

7 0

3 years ago

Cyclopropane, a substance used with oxygen as a general anesthetic, contains only two elements, carbon and hydrogen. When 1.00 g

ELEN [110]

Answer:

CH₂

Explanation:

From the question given above, the following data were obtained:

Mass of compound = 1 g

Mass of CO₂ = 3.14 g

Mass of H₂O = 1.29 g

Empirical formula =?

Next, we shall determine the mass of Carbon and hydrogen present in the compound. This can be obtained as follow:

For Carbon, C:

Mass of CO₂ = 3.14 g

Molar mass of CO₂ = 12 + (2×16)

= 12 + 32

= 44 g/mol

Molar mass of C = 12 g/mol

Mass of C =?

Mass of C = molar mass of C/ Molar mass of CO₂ × Mass of CO₂

Mass of C = 12/44 × 3.14

Mass of C = 0.86 g

For hydrogen, H:

Mass of C = 0.86 g

Mass of compound = 1 g

Mass of H =?

Mass of H = (Mass of compound) – (mass of C)

Mass of H = 1 – 0.86

Mass of H = 0.14 g

Finally, we shall determine the empirical formula of the cyclopropane. This can be obtained as follow:

Mass of C = 0.86 g

Mass of H = 0.14 g

Divide by their molar mass

C = 0.86 / 12 = 0.07

H = 0.14 / 1 = 0.14

Divide by the smallest

C = 0.07 / 0.07 = 1

H = 0.14 / 0.07 = 2

Thus, the empirical formula of cyclopropane is CH₂

8 0

3 years ago

If salt (5. 99 × 10–6 mol) is dissolved in 1. 50 × 10–2 L of water, which expression can be used to find the molarity of the res

Alexus [3.1K]

Molarity can be defined as the moles of solute in a liter of solution. The molarity of the salt solution is $\rm \bold{3.99\;\times\;10^{-4}\;M}$ .

<h3>What is the relation between moles and volume?</h3>

The moles are the mass of substance with respect to the molar mass. The moles and volume relationship can be expressed in terms of molarity.

The molarity can be expressed as:

$\rm Molarity=\dfrac{Moles}{Volume}$