1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Viktor [21]
3 years ago
15

Why are some examples of a chemical reaction not actually foolproof evidence that of a chemical reaction?13, 8th grade, and I'm

doing my science lab report: 
The lab was a chemistry lab. We got a bunch of toxic chemicals and put pairs of them together, recorded the reactions, and wrote balanced equations for each of them and identified what kind of reaction they were. The whole name of the lab is "Evidence of Chemical Reactions", and one of the first analysis questions is "write a paragraph about the kinds of changes you would expect to see if a chemical reaction occurs." I answered this with things like bubble formation, change of color, change of state of matter, etc. Then the next question said "any one of these signs is not always a fool proof indication that a chemical reaction is occurring. give two examples to support this statement." 
what are two examples to support the statement that the commonly known examples of chemical reactions occurring are not always foolproof evidence that chemical reactions are occurring?
Chemistry
1 answer:
kvasek [131]3 years ago
7 0
So basically, the change in color effects the amount of cations in the solution making it a physical change rather than a chemical one, defying the law of conservation of mass! I hope this helped! (The only time the change in color affects the amount of cations is in the Alkaline Earth Metals)

source: college science teacher 
You might be interested in
Which of the following contains a covalent bond?<br> A) BeO<br> B) LiCI<br> C) CN<br> D) MgO
Svetllana [295]

Answer= C) CN contains a covalent bond.

7 0
2 years ago
each body cell of a goldfish contains 94 chromosomes.how many chromosomes are contained in a goldfish sex cell?
Shalnov [3]
47 I believe not 100% sure
8 0
2 years ago
An unknown noble gas has a density of 5.84 g dm-3 at STP. Calculate its molar mass, and so identify the gas.
bagirrra123 [75]

The noble gas is Xenon and its molar mass is 131 g/mol.

<h3>What is the molar mass of the noble gas?</h3>

The molar mass of the noble gas is determined as follows;

Let molar mass of unknown gas be M, and mass of gas be m

Density of the noble gas, ρ = 5.8 g/dm³

density = m/V

At STP;

  • temperature, T = 273.15 K
  • pressure, P = 1 atm
  • molar gas constant, R = 0.0821 L.atmK⁻¹mol⁻¹

From ideal gas equation:

PV = nRT

where n = m/M

PV = mRT/M

M = mRT/PV

M =  0.0821 * 273.15 * 5.84/1

Molar mass of the noble gas = 131 g/mol

The noble gas is Xenon which has molar mass approximately equal to 131 g/mol.

Learn more about molar mass at: brainly.com/question/837939

#SPJ1

6 0
1 year ago
How did coroners handle their responsibilities in the early 1900s? Why was there a need for significant change in the job?
Lorico [155]

Answer:

In the twentieth century, criminologists and forensics strive to summarize the preceding discoveries. In different countries tendencies are beginning to manifest that increase the field of criminological activity in different branches such as criminalistics in Germany; others, penology; and others like the United States, weighed the study as a whole of the science of crime and the science of social reaction provoked by it. In this century, criminology and forensic science had a notable influence on the evolution of criminal law.

Starting in the mid-20th century, a paradigm shift in forensic criminological science was presented, focusing on the study of three aspects: criminal processes, the social environment, and the victim.

Other factors that were taken into account were biosecurity care, which began to have great relevance and greater care since they began to discover infectious diseases transmitted by cadavers to humans.

Approximately in 1939 it was discovered that anthropometric measurements are values that present similarities between different skeleton patterns.

Explanation:

Legal dentistry also addresses the aspect related to “professions” and people's habits, for example, by 1925 it was already possible to identify a smoker by the coloration that the teeth took and the wear on the incisors and canines where the cigar rested. The morphological characteristics of the teeth were, in many cases, used to identify those they called "degenerates", who were the ones who went outside the guidelines of psychic "normality" of the time; among these were prostitutes, thieves, who according to the author had a considerable volume in the molars, the canines were triangular and long, like the upper central incisors that in some reached 8 mm.

3 0
3 years ago
How many grams of oxygen are required too burn 8.8g of c3h8?
hichkok12 [17]
From the balanced equation: 
<span>1mol C3H8 requires 5mol O2 for combustion </span>
<span>Molar mass C3H8 = 44g/mol </span>
<span>8.8g C3H8 = 8.8/44 = 0.2mol C3H8 </span>
<span>This will require 5*0.2 = 1.0mol O2 </span>
<span>Molar mass O2 = 32g/mol </span>
<span>Therefore 32g of O2 required.


</span>
4 0
3 years ago
Other questions:
  • When performing a flame test using the method described in the manual, you complete the flame test of KNO3 and find a yellow col
    7·1 answer
  • Suppose you had 1.0 mol samples the following gases at STP. If the volume of each of the samples of gas was reduced to one tenth
    8·2 answers
  • In class, it was mentioned that at 25 °C, the pH of pure water is 7.00 becuase Kw = 1.0 × 10−14. At other temperatures, the pH v
    5·1 answer
  • The poison dart from the jungle can kill its prey with a slim from its skin. this is an example of a
    6·1 answer
  • Calculate the pH of a solution with [H₃O⁺] = 1 × 10¯⁴ M to the correct number of decimal places.
    12·1 answer
  • PLZ HELP!!
    8·1 answer
  • Glucose is a product of photosynthesis. where do the carbon atoms in glucose come from?
    15·2 answers
  • Does anyone know what order?
    7·2 answers
  • Chemically balance the equation: Mg(HCO3)2 + HCL --&gt; MgCl2 + CO2 + H2O​
    8·1 answer
  • What kind of radioactive element is useful for dating an object?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!