19.The Alkali and Alkaline Earth metals belong to which columns, respectively?

During which step of meiosis do the homologous chromosomes line up in the middle of the cell?

777dan777 [17]

Answer:

It is D

metaphase 1

Explanation:

in metaphase chromosome line up in the middle.

3 0

3 years ago

What do methanol (CH2O), ethanoic acid (C2H4O2), and glucose (C3H6O3) all have in common?

tatyana61 [14]

Answer:

d

Explanation:

Carbohydrates are compounds containing carbon, hydrogen, and oxygen. Therefore, a is true.

An empirical formula is the simplest ratio of atoms present in a compound. Therefore, C2H4O2 and C3H6O3, (if you simplified them like you would a fraction) would be CH2O. Therefore b is correct,

They also have the same % composition, with a ratio of 1 carbon : 2 hydrogen : 1 oxygen. Therefore, c is correct.

Since a, b and c are all correct, the answer is d, all of the above are true.

6 0

4 years ago

The painkiller, Advil® contains the active ingredient ibuprofen (IB), which has a pKb of

denis23 [38]

This problem is providing the basic dissociation constant of ibuprofen (IB) as 5.20, its pH as 8.20 and is requiring the equilibrium concentration of the aforementioned drug by giving the chemical equation at equilibrium it takes place. The obtained result turned out to be D) 4.0 × 10−7 M, according to the following work:

First of all, we set up an equilibrium expression for the given chemical equation at equilibrium, in which water is omitted for it is liquid and just aqueous species are allowed to be included:

$Kb=\frac{[IBH^+][OH^-]}{[IB]}$

Next, we calculate the concentration of hydroxide ions and the Kb due to the fact that both the pH and pKb were given:

$pOH=14-8.20=5.80$

$[OH^-]=10^{-5.8}=1.585x10^{-6}M$

$Kb=10^{-5.20}=6.31x10^{-6}$

Then, since the concentration of these ions equal that of the conjugated acid of the ibuprofen (IBH⁺), we can plug in these and the Kb to obtain:

$6.31x10^{-6}=\frac{(1.585x10^{-6})(1.585x10^{-6})}{[IB]}$

Finally, we solve for the equilibrium concentration of ibuprofen:

$[IB]=\frac{(1.585x10^{-6})(1.585x10^{-6})}{6.31x10^{-6}}=4.0x10^{-7}$

Learn more:

(Weak base equilibrium calculation) brainly.com/question/9426156

4 0

3 years ago

calculate the heat required in joules to convert 18.0 grams of water ice at a temperature of -20 c to liquid water at the normal

KIM [24]

Answer:

Explanation:

Heat required to convert ice to ice at 0⁰C

= mass x specific heat x rise in temperature

= 18 x 2.09 x 20

= 752.4 J .

heat required to convert ice at 0⁰C to water at 0⁰C

mass x latent heat of fusion

= 18 x 336

= 6048 J

Heat required to increase the temperature of water to 100⁰C

= 18 x 4.2 x 100

= 7560 J

Total heat required

7560 + 6048 + 752.4

= 14360.4 J

7 0

3 years ago

What is the main source of energy in stars?

enot [183]

Answer:

nuclear fusion

4 0

4 years ago

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