Ask question

Ask question

All categories

3 years ago

6

Another real-world example of a change is rust. Rust is iron oxide (Fe2O3), which results when iron is exposed to oxygen in the

air. What are some indicators of rusting? Check all that apply. A) production of light B) color change C) formation of a solid D) formation of a gas

2 answers:

natita [175]3 years ago

8 0

Answer:

c

Explanation:

IrinaVladis [17]3 years ago

5 0

Answer:

c

Explanation:

You might be interested in

Draw the structure of the compound identified by the following simulated 1H and 13C NMR spectra. The molecular formula of the co

Luba_88 [7]

Answer: 4-allylanisole

Explanation: The doublets behind the 7 ppm belongs to the

para-substituted benzene ring. The three single-proton multi-plets around 5−6 ppm predicts that there has to be a single subsituted alkene group

A single plus a doublet around 3-4 ppm belongs to CH3 and CH2 Groups as they could be attached to the subsituted alkene group.

Moreover the interpretation of the NMR that there is no peak with a higher intensity for >180 ppm represents an absence of Carbonyl group.

The Predicted Number is attached from a chemical database along with their peaks information

6 0

3 years ago

What is the endpoint of a titration?Select one:When there is no acid and all base.When the amount of acid and base are equal.Whe

user100 [1]

Answer:

The correct option is: When the amount of acid and base are equal

Explanation:

Titration is an analytic method that is used to determine the concentration of an<em> unknown solution</em>, called <em>titrand</em>.

In this method, standard solution of known concentration, called <em>titrant</em>, is taken in the burette and added drop-wise to the titrand solution in the flask, until the endpoint is reached.

In case of an acid-base titration, a <em>pH indicator</em> is used, which changes the color of the solution when the endpoint is reached.

<u>The </u><u>endpoint</u><u> indicates the </u><u>equivalence point</u><u> of an acid-base titration, where the </u><em><u>concentration of the acid and base is equal</u></em><u>. </u>

<u>Therefore, the </u><u>correct option</u><u> is: </u><u>When the amount of acid and base are equal</u>

3 0

3 years ago

The empirical formula of an organic compound is C2H4O. The molecular mass of the compound is 176g/mol.

Brrunno [24]

Answer:

The molecular formula of the compound is $C_{8}H_{16}O_{4}$ . The molecular formula is obtained by the following expression shown below

$\textrm{Molecular formula }= n\times \textrm{Empirical formula}$

Explanation:

Given molecular mass of the compound is 176 g/mol

Given empirical formula is $C_{2}H_{4}O$

Atomic mass of carbon, hydrogen and oxygen are 12 u , 1 u and 16 u respectively.

Empirical formula mass of the compound = $\left ( 2\times12+4+16 \right ) \textrm{ u} = 44 \textrm{ g/mol}$

$n = \displaystyle \frac{\textrm{Molecular formula mass}}{\textrm{Empirical formula mass}} \\n = \displaystyle \frac{176}{44} = 4$

$\textrm{Molecular formula }= n\times \textrm{Empirical formula}$

Molecular formula = 4 $\times$ $C_{2}H_{4}O$

Molecular formula is $C_{8}H_{16}O_{4}$

6 0

2 years ago

Part A Find ΔS∘ for the reaction between nitrogen gas and hydrogen gas to form ammonia: 12N2(g)+32H2(g)→NH3(g) Express your answ

inessss [21]

Answer:

$\Delta S^{0}$ for the given reaction is -99.4 J/K

Explanation:

Balanced reaction: $\frac{1}{2}N_{2}(g)+\frac{3}{2}H_{2}(g)\rightarrow NH_{3}(g)$

$\Delta S^{0}=[1mol\times S^{0}(NH_{3})_{g}]-[\frac{1}{2}mol\times S^{0}(N_{2})_{g}]-[\frac{3}{2}mol\times S^{0}(H_{2})_{g}]$

where $S^{0}$ represents standard entropy.

Plug in all the standard entropy values from available literature in the above equation:

$\Delta S^{0}=[1mol\times 192.45\frac{J}{mol.K}]-[\frac{1}{2}mol\times 191.61\frac{J}{mol.K}]-[\frac{3}{2}mol\times 130.684\frac{J}{mol.K}]=-99.4J/K$

So, $\Delta S^{0}$ for the given reaction is -99.4 J/K

7 0

3 years ago

What does the atomic mass of an element on the periodic table represent?

Lynna [10]

The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.

Atomic mass = Number of protons + number of neutrons

Hope this helps!

3 0

2 years ago