Answer:
C₂H₆(g) + O₂(g) ⇒ CO₂(g) + H₂O(l)
Explanation:
Which of the following are combustion reactions?
NaNO₃(aq) ⇒ Na⁺(aq) + NO₃⁻(aq)
NO. This is a dissociation reaction.
C₂H₆(g) + O₂(g) ⇒ CO₂(g) + H₂O(l)
YES. This is a combustion reaction because a compound reacts with oxygen to form carbon dioxide and water.
Mg(s) + HCl (aq) ⇒ H₂(g) + MgCl₂(aq)
NO. This is a single displacement reaction.
HCl(aq) + NaOH (aq) ⇒ HOH(l) + NaCl(s)
NO. This is a neutralization reaction.
Answer:
The second option is correct.
The question is incomplete, here is the complete question:
A chemist makes 600. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a stock solution of 0.00154 mol/L magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.
<u>Answer:</u> The concentration of chemist's working solution is 
<u>Explanation:</u>
To calculate the molarity of the diluted solution (chemist's working solution), we use the equation:
where,
are the molarity and volume of the stock magnesium fluoride solution
are the molarity and volume of chemist's magnesium fluoride solution
We are given:
Putting values in above equation, we get:
Hence, the concentration of chemist's working solution is
Answer:
- <u>The last digit, 8, is the uncertain one.</u>
Explanation:
Every measurement has an uncertainty associated with the instrument used to measure.
The measurement represented by 5.678 grams has 4 significant digits: all the non-zero digits in a measurement are significant (non-zero digits and zeros between non-zero digits are always significant).
When you use a scale to measure the mass of an object, such scale has an appreciation and the last number that you can read is between two possible numbers, i.e. the digit 8 in the given measurement could have been a little bigger or a little smaller, so the real measurement could have been something between 5.677 . . . or 5.678 . . .
The last digit in any measurement is always uncertain.
