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3 years ago

What is indirect evidence in science

1 answer:

8 0

Definition of indirect evidence. : evidence that establishes immediately collateral facts from which the main fact may be inferred : circumstantial evidence.

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Calculate the molarity of an hcl solution if a 10.00 ml sample requires 25.24 ml of a 1.600 m naoh solution to be neutralized.

AlladinOne [14]

Answer:

The molarity of the HCl solution should be 4.04 M

Explanation:

Step 1: Data given

volume of HCl solution = 10.00 mL = 0.01 L

volume of a 1.6 M NaOH solution = 25.24 mL = 0.02524 L

Step 2: The balanced equation

HCl + NaOH → NaCL + H2O

Step 3: Calculate molarity of HCl

n1*C1*V1 = n2*C2*V2

Since the mole ratio for HCl and NaOH is 1:1 we can just write:

C1*V1 =C2*V2

⇒ with C1 : the molarity of HCl = TO BE DETERMINED

⇒ with V1 = the volume og HCl = 10 mL = 0.01 L

⇒ with C2 = The molarity of NaOH = 1.6 M

⇒ with V2 = volume of NaOH = 25.24 mL = 0.02524 L

C1 * 0.01 = 1.6 * 0.02524

C1 = (1.6*0.02524)/0.01

C1 = 4.04M

The molarity of the HCl solution should be 4.04 M

6 0

3 years ago

there is a total of seventeen constitutional isomers for the molecular formula c5h13n. draw the skeletal formula of all three co

MAXImum [283]

Amines are derivatives of Ammonia (NH₃) in which atleast one hydrogen atom is replaced by an alkyl group. Amines are further classifies as;

Primary Amines:
In primary amines the nitrogen atom is attached to two hydrogen atoms and one alkyl group.

Secondary Amines:
In secondary amines the nitrogen atom is attached to two alkyl groups and one hydrogen atom.

Tertiary Amines:
In tertiary amines the nitrogen atom is attached to three alkyl groups, hence it has no hydrogen atom.

Below are three isomers of tertiary amines with molecular formula C₅H₁₃N.

5 0

3 years ago

Which of the following are strongly hydrogen bonded in the liquid phase? A) nitrilesB) esters C) secondary amides D) acid chlori

-Dominant- [34]

Answer: Option (C) is the correct answer.

Explanation:

Chemical formula of a secondary amide is R'-CONH-R, where R and R' can be same of different alkyl or aryl groups. Here, the hydrogen atom of amide is attached to more electronegative oxygen atom of the C=O group.

Therefore, the hydrogen atom will be more strongly held by the electronegative oxygen atom. As a result, there will be strongly hydrogen bonded in the liquid phase of secondary amide.

Whereas chemical formula of nitriles is RCN, ester is RCOOR' and acid chlorides are RCOCl. As no hydrogen bonding occurs in any of these compounds because hydrogen atom is not being attached to an electronegative atom.

Thus, we can conclude that secondary amides are strongly hydrogen bonded in the liquid phase.

6 0

3 years ago

What organ is very important in human body

Lostsunrise [7]

Answer:

The brain is arguably the most important organ in the human body. It controls and coordinates actions and reactions, allows us to think and feel, and enables us to have memories and feelings—all the things that make us human.

Explanation:

8 0

2 years ago

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The text describes the first three reactions of a metabolic pathway. Complete the sentences. Not all the terms will be placed. I

Nina [5.8K]

In reaction 1 of the Krebs cycle, acetyl‑CoA formed in the pyruvate dehydrogenase reaction condenses with the four‑carbon compound to form citrate with the elimination of coenzyme A. Since the product has three carboxyl groups, this pathway is referred to as the cycle. In reaction 2 of the Krebs cycle, this product then undergoes to form isocitrate. The enzyme is called aconitase because the compound cis‑aconitate is the intermediate product of the reaction. Reaction 3 eliminates CO2 to form the five‑carbon dicarboxylic acid α-cetoglutarate. Oxidation also occurs, with electrons transferred from the substrate to COO- . Consequently, this reaction is an oxidative decarboxylation.

In the image, you can see the reaction 2 in Krebs cycle is a two steps reaction with an intermediate cis-aconitase and a product called isocitrate.

4 0

3 years ago

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