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
A student builds a model of a race car. The scale is 1:15. In the scale model, the car is 8 cm tall. How tall is the actual car?
<h2>Answers:</h2>
<h3>A. 120 cm</h3>
#CarryOnLearning
Answer: 502 Joules
Explanation:
To calculate the mass of water, we use the equation:
Density of water = 1 g/mL
Volume of water = 40.0 mL
Putting values in above equation, we get:
When metal is dipped in water, the amount of heat released by lead will be equal to the amount of heat absorbed by water.
The equation used to calculate heat released or absorbed follows:
q = heat absorbed by water
= mass of water = 40.0 g
= final temperature of water = 20.0°C
= initial temperature of water = 17.0°C
= specific heat of water= 4.186 J/g°C
Putting values in equation 1, we get:
![q=40.0\times 4.186\times (20.0-17.0)]](https://tex.z-dn.net/?f=q%3D40.0%5Ctimes%204.186%5Ctimes%20%2820.0-17.0%29%5D)
Hence, the joules of heat were re-leased by the lead is 502
Answer:
1) Big Bang Theory
2) we are in a phase of the big bang theory
Explanation:
So for number 1 the answer is the -big bang theory- and number 2 there is a theory that pretty much says that were in a constant cycle. what I mean is theoretically in a couple million years the entire universe will form together again into another dense ball and repeat the process. So basically the universe is still in the "expanding phase" and that's what backs up the theory of the big bang (the fact that were in one of the big bang theory's "phases")
