I need help with this ?

What is the purpose of the subscripts, or small numbers, in a chemical formula?

dlinn [17]

Answer: To show the number of atoms present.

Explanation: As in CO² (Carbon dioxide), there is a small 2 next to the symbol "O" (oxygen) to explain that there are two oxygen atoms.

7 0

3 years ago

Al(s) + NiSO4(aq) Balance

irinina [24]

Answer:

$2Al(s) + 3NiSO4 --> Al2(SO4)3 + 3Ni$

Explanation:

This reaction type is a single replacement. The format of a single replacement is:

$A+BC --> B+AC$

A= Al

B= Ni

C= SO

The coefficient 3 for Ni would become a subscript for AC. After you plug those into the reaction you need to count how many of each are on the left side and try to get the same number on the right side. Both sides must be equal to have a balanced equation.

8 0

3 years ago

What is the concentration of OH − and pOH in a 0.00066 M solution of Ba ( OH ) 2 at 25 ∘ C? Assume complete dissociation.

Allushta [10]

Answer: The hydroxide ion concentration and pOH of the solution is $1.32\times 10^{-3}M$ and 2.88 respectively

Explanation:

We are given:

Concentration of barium hydroxide = 0.00066 M

The chemical equation for the dissociation of barium hydroxide follows:

$Ba(OH)_2\rightarrow Ba^{2+}+2OH^-$

1 mole of barium hydroxide produces 1 mole of barium ions and 2 moles of hydroxide ions

pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution

To calculate pOH of the solution, we use the equation:

$pOH=-\log[OH^-]$

We are given:

$[OH^-]=(2\times 0.00066)=1.32\times 10^{-3}M$

Putting values in above equation, we get:

$pOH=-\log(1.32\times 10^{-3})\\\\pOH=2.88$

Hence, the hydroxide ion concentration and pOH of the solution is $1.32\times 10^{-3}M$ and 2.88 respectively

3 0

3 years ago

Write a scientific explanation that explains how modern whales differ from their ancient ancestors THIS IS A CER so can i get a

PolarNik [594]

Answer:

Modern whales evolved by natural selection over long time periods through descent from common ancestors

Explanation:

According to the evolutionary theory proposed by Darwin, natural selection is a biological process by which organisms adapt and change in response to their environment. In this case, ancient whales that were better suited to environmental conditions survived and produced more offspring than non-adapted individuals. In consequence, predominant adaptive traits observed in modern whales were favored by natural selection in the past, while unsuccessful phenotypes progressively disappeared.

3 0

3 years ago

If 2.68 g of benzaldehyde are involved with the mixed aldol condensation reaction, how many moles of benzaldehyde are present? R

Zielflug [23.3K]

Answer:

The number of moles of benzaldehyde = 0.0253 moles

Explanation:

The molecular formula of benzaldehyde is C₇H₆O

Its molecular mass is calculated from the atomic masses of the constituent atoms.

C = 12.0 g: H = 1.0 g; O = 16.0 g

Molecular mass = ( 12 * 7) + (1 * 6) + (16 * 1) = 106.0 g/mol

Number of moles of substance = mass of substance/ molar mass of the substance

mass of benzaldehyde = 2.68; molar mass = 106.0 g/mol

Number of moles of benzaldehyde = 2.68 g/ 106 g/mol = 0.0253 moles

Therefore, the number of moles of benzaldehyde = 0.0253 moles

8 0

3 years ago