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3 years ago

Can you please help with question 1 and 4

Chemistry

2 answers:

larisa86 [58]3 years ago

5 0

Answer:

i) 24.305 u

iv) The number of protons determines an element's atomic number and is used to distinguish one element from another.

dmitriy555 [2]3 years ago

3 0

Answer:

1) 24

2)protons

Explanation:

1) magnesium Ar

2) atomic number

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Isoleucine, leucine, and lysine are three examples of amino acids that the body can not make in sufficient quantity. How are the

Natalija [7]

Answer:

Leucine, isoleucine and lysine are classified as essential amino acids.

Explanation:

Amino acids are the important biomolecules in which an alpha-carbon is attached to a side chain R, two functional groups and one hydrogen.

The two functional groups are: amine group (-NH₂) and carboxyl group (-COOH).

There are total 21 amino acids in a human body. They can be divided into two types: Essential amino acids and Nonessential amino acids

Essential amino acids are the 9 amino acids that can not be produced by the human body and thus has to be taken through diet.

Example: leucine, isoleucine, lysine.

Therefore, leucine, isoleucine and lysine are classified as essential amino acids.

8 0

3 years ago

Read 2 more answers

Una disolución contiene 50 gramos de KOH en 0.25 L de Determine la Molaridad de la disolución

snow_tiger [21]

Answer:

1. 3.56 M.

2. 0.99 M.

Explanation:

¡Hola!

1. En este caso, dado que la molaridad de una solution es calculada por medio de la siguiente ecuación:

$M=\frac{n}{V}$

Es posible calcular la molaridad de 50 gramos de hidróxido de potasio primero calculando las moles en dicha masa por medio de la masa molar:

$n=50.0gKOH*\frac{1molKOH}{56.11gKOH}=0.891molKOH$

Luego, dado el volumen de la solución, podemos calcular la molaridad:

$M=\frac{0.891mol}{0.25L}=3.56M$

2. En este segundo ejercicio, procedemos de la misma manera, pues primero calculamos las moles de nitrato de potasio:

$n=75gKNO_3\frac{1molKNO_3}{101.1gKNO_3}=0.742mol$

Luego, calculamos la molaridad justo como se hizo anteriormente:

$M=\frac{0.742mol}{0.35L} \\\\M=0.99M$

Best regards!

3 0

3 years ago

The balanced equation for the reaction of aqueous Pb(ClO3)2 with aqueous NaI is Pb(ClO3)2(aq)+2NaI(aq)⟶PbI2(s)+2NaClO3(aq) What

ryzh [129]

Answer : The mass of $PbI_2$ precipitate produced will be, 9.681 grams.

Explanation : Given,

Molarity of NaI = 0.210 M

Volume of solution = 0.2 L

Molar mass of $PbI_2$ = 461.01 g/mole

First we have to calculate the moles of $NaI$ .

$\text{Moles of }NaI=\text{Molarity of }NaI\times \text{Volume of solution}=0.210M\times 0.2L=0.042moles$

Now we have to calculate the moles of $PbI_2$ .

The balanced chemical reaction is,

$Pb(ClO_3)_2(aq)+2NaI(aq)\rightarrow PbI_2(s)+2NaClO_3(aq)$

From the balanced reaction we conclude that

As, 2 moles of $NaI$ react to give 1 mole of $PbI_2$

So, 0.042 moles of $NaI$ react to give $\frac{0.042}{2}=0.021$ moles of $PbI_2$

Now we have to calculate the mass of $PbI_2$ .

$\text{Mass of }PbI_2=\text{Moles of }PbI_2\times \text{Molar mass of }PbI_2$

$\text{Mass of }PbI_2=(0.021mole)\times (461.01g/mole)=9.681g$

Therefore, the mass of $PbI_2$ precipitate produced will be, 9.681 grams.

6 0

4 years ago

How can you tell which compound in a solution is the solvent? (own words please)

Free_Kalibri [48]

Answer:

The way you can know which compound in a solution is a solvent is by usually just determining which substance is a solute and which is a solvent. The solute is when it is dissolved and it takes on the characteristics of the solvent.

Explanation:

Hope this helps!

3 0

3 years ago

Do the tests performed to identify DNA exclude the presence of RNA?

Ratling [72]

DNA and RNA can also be ISOLATED from the same biological sample.

So the answer is no, both DNA and RNA are together.

5 0

3 years ago

Read 2 more answers

Can you please help with question 1 and 4​

Can you please help with question 1 and 4