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3 years ago

Evidence of a chemical change does NOT include

Chemistry

2 answers:

Elena-2011 [213]3 years ago

4 0

C. change in shape is the right answer

horrorfan [7]3 years ago

3 0

C is the correct answer for this question. since it is a physical change

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Consider the reaction shown.

Allushta [10]

Answer:

4.43 g Cl₂

Explanation:

To find the mass of Cl₂, you need to (1) convert moles HCl to moles Cl₂ (via the mole-to-mole ratio from equation coefficients) and then (2) convert moles Cl₂ to grams (via the molar mass). It is important to arrange the conversions/ratios in a way that allows for the cancellation of units. The final answer should have 3 significant figures like the given value.

4 HCl(g) + O₂(g) -----> 2 Cl₂(g) + 2 H₂O(g)
^ ^

Molar Mass (Cl₂): 2(35.453 g/mol)

Molar Mass (Cl₂): 70.906 g/mol

0.125 moles HCl 2 moles Cl₂ 70.906 g
-------------------------- x ---------------------- x ------------------- = 4.43 g Cl₂
4 moles HCl 1 mole

6 0

2 years ago

Provide the IUPAC names for

ollegr [7]

Answer:

For a: The IUPAC name of the compound is N-ethylethaneamide.

For b: The IUPAC name of the compound is N,N-diethylmethaneamide.

For c: The IUPAC name of the compound is ethyl pentanoate

Explanation:

To name a compound, first look for the longest possible carbon chain.

For a:

Amide group is a type of functional group where an amine group is attached to a carbonyl group. The general formula of amide is $R-CO-NH_2$ , where R is an alkyl or aryl group.

In part (a), the alkyl group has 2 carbon atoms and thus, the prefix used is 'eth-'

Also, an ethyl substituent is directly attached to N-atom. It is an alkane structured hydrocarbon thus, the suffix used will be '-ane'

Hence, the IUPAC name of the compound is N-ethylethaneamide.

For b:

Amide group is a type of functional group where an amine group is attached to a carbonyl group. The general formula of amide is $R-CO-NH_2$ , where R is an alkyl or aryl group.

In part (b), the alkyl group has 1 carbon atoms and thus, the prefix used is 'meth-'

Also, two ethyl substituents are directly attached to N-atom. It is an alkane structured hydrocarbon thus, the suffix used will be '-ane'

Hence, the IUPAC name of the compound is N,N-diethylmethaneamide.

For c:

Esters are a kind of organic molecules having functional groups, $R-COO-R'$ where R and R' are the alkyl or aryl groups. They are formed by the combination of alcohol and carboxylic acid.

These functional group compounds are named in two words which is alkyl alkanoates, where alkyl refers to the alcoholic part and alkanoate refers to the carboxylic acid part of the molecule. The numbering of the parent chain in esters is done from the carboxylic carbon. The alkyl part is not given any numbers.

In part (c), there are 5 carbon atoms present in a straight chain and thus, the prefix used is 'pent-'

Also, an ethyl group forms the alcoholic part.

Hence, the IUPAC name of the compound is ethyl pentanoate

6 0

3 years ago

In a sample of liquid water (H2O), which property differs among the water molecules?

garik1379 [7]

In a sample liquid water, a property that differs among the water molecules is its own orientation and space. The explanation of the answer to the question is because the number of the oxygen and hydrogen atoms and the hydrogen and atoms’ arrangement will never change and will always be the same for each of the water molecule. The strength of the bond of it also does not change and stays the same.

3 0

3 years ago

How is a gas's ability to fill a container different from that of a liquid or a solid?

svp [43]

Well a solid and a liquid is completely different from a gas. For a gas you need to have an air tight seal in order for the gas to stay in, or a special type of container so the gas doesn't decompose the container. And a liquid or a solid it's self explanatory. With some liquids you need special containers to hold the liquid so it doesn't decompose the container it's in.

8 0

3 years ago

Does iron always have a charge of 2+ when it forms an ion

Usimov [2.4K]

Answer:

Roman numeral notation indicates charge of ion when element commonly forms more than one ion. For example, iron(II) has a 2+ charge; iron(III) a 3+ charge.

Explanation:

8 0

3 years ago