Answer: The second choice
Explanation: The question is most likely asking what the arrow's pointing at, and it's right at the meeting point for lines x and y. Lines x and y would be the common ancestors of the point the arrow is showing since they're above the point and meet up to the point.
Answer:
sodium ion has smaller radius than a atom.
Explanation:
<span>The energy (E) per photon is expressed by Planck's equation: E = hf, where f is
the frequency and h is Planck's constant, experimentally determined to be
6.625 * 10**-34 joule-seconds. So to find E, we multiply h by the frequency
and obtain E = hf = (6.625 * 10**-34)(7.0 * 10**14) = 46.375 * 10**-20 joule
or in standard notation, E = 4.6375 * 10**-19 joule per photon.
Hope this answers your question.Sorry if I calculated wrong.</span>
Answer:
74mL
Explanation:
Given parameters:
Molar mass of citric acid = 192g/mol
Molar mass of baking soda = 84g/mol
Concentration of citric acid = 0.8M
Mass of baking powder = 15g
Unknown parameters:
Volume of citric acid = ?
Solution
Equation of the reaction:
C₆H₈O₇ + 3NaHCO₃ → Na₃C₆H₅O₇ + 3H₂O + 3CO₂
Procedure:
- We work from the known parameters to the unknown. From the statement of the problem, we can approach the solution from the parameters of the baking powder.
- From the baking powder, we can establish a molar relationship between the two reactants. We employ the mole concept in this regard.
- We find the number of moles of the baking powder that went into the reaction using the expression below:
Number of moles = 
Number of moles =
= 0.179mole
- From the equation of the reaction, we can find the number of moles of the citric acid:
3 moles of baking powder reacted with 1 mole of citric acid
0.179 moles of baking powder would react with
:
This yields 0.059mole of citric acid
- To find the volume of the citric acid, we use the mole expression below:
Volume of citric acid = 
Volume of citric acid =
= 0.074L
Expressing in mL gives 74mL