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3 years ago

The diameter of a carbon atom is 0.000000000154 m. What is this number expressed in scientific notation?

Chemistry

2 answers:

Viktor [21]3 years ago

8 0

1.54 x 10^-10 (ten to the negative tenth power)

elena-s [515]3 years ago

3 0

The answer to your question

1.54*10^-10m

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When sodium reacts with chlorine, sodium chlorine is produced Andrew represented this reaction with this equation

Paha777 [63]

Answer:

sodium chloride is produced= Na+ Cl⇒ NaCl

Explanation: when sodium reacts with chlorine, sodium gives out its electron to chlorine for them to become stable. in the end they form an ionic compound known as sodium chloride

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3 years ago

Phosphoric acid is a triprotic acid ( K a1 = 6.9 × 10 − 3 Ka1=6.9×10−3, K a2 = 6.2 × 10 − 8 Ka2=6.2×10−8, and K a3 = 4.8 × 10 −

irina1246 [14]

<u>Answer:</u> To calculate the pH of the buffer composed of $H_2PO_4^-\text{ and }HPO_4^{-2}$ , we use the $K_a2$

<u>Explanation:</u>

Phosphoric acid is a triprotic acid and it will undergo three dissociation reaction each having their respective dissociation constants.

The chemical equation for the first dissociation reaction follows:

$H_3PO_4\rightleftharpoons H_2PO_4^-+H^+;K_a1=6.9\times 10^{-3}$

The chemical equation for the second dissociation reaction follows:

$H_2PO_4^-\rightleftharpoons HPO_4^{2-}+H^+;K_a2=6.2\times 10^{-8}$

The chemical equation for the third dissociation reaction follows:

$HPO_4^{2-}\rightleftharpoons PO_4^{3-}+H^+;K_a3=4.8\times 10^{-13}$

To form a buffer composed of $H_2PO_4^-\text{ and }HPO_4^{-2}$ , we use the $K_a$ of second dissociation process

To calculate the $pK_a$ , we use the equation:

$pK_a=-\log (K_a)\\\\pK_a=-\log(6.2\times 10^{-8})\\\\pK_a=7.21$

To calculate the pH of buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a2+\log(\frac{[\text{conjugate base}]}{[\text{weak acid}]})$

$pH=pK_a2+\log(\frac{[HPO_4^{2-}]}{[H_2PO_4^-]})$

We are given:

$pK_a2$ = negative logarithm of second acid dissociation constant of phosphoric acid = 7.21

$[HPO_4^{2-}]$ = concentration of conjugate base

$[H_2PO_4^{-}]$ = concentration of weak acid

Hence, to calculate the pH of the buffer composed of $H_2PO_4^-\text{ and }HPO_4^{-2}$ , we use the $K_a2$

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4 years ago

Investigators are studying a protein that must be phosphorylated to be activated. Which method could be used to separate the pho

Roman55 [17]

Answer:

There is two common methods to separate a phosphorylated protein from the proteins who does not have the phosphate group.

1. Western Blot test

The Western blot test is a method where we separate of the biological sample with SDS- PAGE (electrophoresis method) and then we transfer to a nitrocellulose membrane. We use a phospho-specific antibody to identify the protein of interest.

2. The ELISA test

this test is also a powerful method for measuring protein phosphorylation. Elisa test is more are quantitative than Western blot test and also shows great advantage in studies related with kinase activity. In this test we use a capture antibody specific for the desired protein, independent of the phosphorylation state. The target protein is binded to the antibody-coated plate. and finally a detection antibody specific for the phosphorylation site analyzed is added. In these test it is possible to use colorimetric or fluorometric detection.

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3 years ago

The temperature in the laboratory is posted as 251k What is the temperature in degrees Celsius

lakkis [162]

I see you have access to the internet. Google 'Kelvin to C', and input 251. You'll get -22.15.

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4 years ago

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Earth's polar regions have cold, dry climates because the sun's rays are at a ?

Solnce55 [7]

Answer:

<h3>not reaching to the poles</h3>