Answer:
What group of people ay?
Maybe look at their differences in appearance: height, size, weight, skin color, clothing choice?
Answer:
648.5 mL
Explanation:
Here we will assume that the pressure of the gas is constant, since it is not given or specified.
Therefore, we can use Charle's law, which states that:
"For an ideal gas kept at constant pressure, the volume of the gas is proportional to its absolute temperature"
Mathematically:
![\frac{V}{T}=const.](https://tex.z-dn.net/?f=%5Cfrac%7BV%7D%7BT%7D%3Dconst.)
where
V is the volume of the gas
T is its absolute temperature
The equation can be rewritten as
![\frac{V_1}{T_1}=\frac{V_2}{T_2}](https://tex.z-dn.net/?f=%5Cfrac%7BV_1%7D%7BT_1%7D%3D%5Cfrac%7BV_2%7D%7BT_2%7D)
where in this problem we have:
is the initial volume of the gas
is the initial temperature
is the final temperature
Solving for V2, we find the final volume of the gas:
![V_2=\frac{V_1 T_2}{T_1}=\frac{(490)(315)}{238}=648.5 mL](https://tex.z-dn.net/?f=V_2%3D%5Cfrac%7BV_1%20T_2%7D%7BT_1%7D%3D%5Cfrac%7B%28490%29%28315%29%7D%7B238%7D%3D648.5%20mL)
Answer:
A
Explanation:
To label an element correctly using a combination of the symbol, mass number and atomic number furnishes some important information about the element.
We can obtain these information from the element provided that correct labeling of the element is presented. Firstly, after writing the symbol of the element, the atomic number is placed as a subscript on the left while the mass number of the atomic mass is placed as a superscript on the same left.
Looking at the question asked, we have the element symbol in the correct position as Ca, with 42 also in the correct position which is the mass number. The third number which is 20 is thus the atomic number of the element.
Answer:
We need 0.375 mol of CH3OH to prepare the solution
Explanation:
For the problem they give us the following data:
Solution concentration 0,75 M
Mass of Solvent is 0,5Kg
knowing that the density of water is 1g / mL, we find the volume of water:
![d = \frac{g}{mL} \\\\ V= \frac{g}{d} = \frac{500g}{1 \frac{g}{mL} } = 500mL = 0,5 L](https://tex.z-dn.net/?f=d%20%3D%20%5Cfrac%7Bg%7D%7BmL%7D%20%5C%5C%5C%5C%20V%3D%20%5Cfrac%7Bg%7D%7Bd%7D%20%20%3D%20%5Cfrac%7B500g%7D%7B1%20%5Cfrac%7Bg%7D%7BmL%7D%20%7D%20%3D%20500mL%20%3D%200%2C5%20L)
Now, find moles of
are needed using the molarity equation:
therefore the solution is prepared using 0.5 L of H2O and 0.375 moles of CH3OH, resulting in a concentration of 0,75M