On temperature 25°C (298,15K) and pressure of 1 atm each gas has same amount of substance:
n(gas) = p·V ÷ R·T = 1 atm · 20L ÷ <span>0,082 L</span>·<span>atm/K</span>·<span>mol </span>· 298,15 K
n(gas) = 0,82 mol.
1) m(He) = 0,82 mol · 4 g/mol = 3,28 g.
d(He) = 10 g + 3,28 g ÷ 20 L = 0,664 g/L.
2) m(Ne) = 0,82 mol · 20,17 g/mol = 16,53 g.
d(Ne) = 26,53 g ÷ 20 L = 1,27 g/L.
3) m(CO) = 0,82 mol ·28 g/mol = 22,96 g.
d(CO) = 32,96 g ÷ 20L = 1,648 g/L.
4) m(NO) = 0,82 mol ·30 g/mol = 24,6 g.
d(NO) = 34,6 g ÷ 20 L = 1,73 g/L.
The moles of chromium (iii) nitrate produced is calculated as follows
write the equation for reaction
3 Pb(NO3)2 + 2 Cr = 2 Cr(NO3)3 + 3 Pb
by use of mole ratio between Pb(NO3)2 to Cr(NO3)3 which is 3 : 2 the moles of Cr(NO3)3 is therefore
= 0.85 x2 /3 = 0.57 moles
<u>Answer:</u> The new concentration of lemonade is 3.90 M
<u>Explanation:</u>
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of lemonade solution = 2.66 M
Volume of solution = 473 mL
Putting values in equation 1, we get:

Now, calculating the new concentration of lemonade by using equation 1:
Moles of lemonade = 1.26 moles
Volume of solution = (473 - 150) mL = 323 mL
Putting values in equation 1, we get:

Hence, the new concentration of lemonade is 3.90 M
<u>Answer:</u> The electronic configuration of the elements are written below.
<u>Explanation:</u>
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
For the given options:
- <u>Option a:</u> Carbon (C)
Carbon is the 6th element of the periodic table. The number of electrons in carbon atom are 6.
The electronic configuration of carbon is 
- <u>Option b:</u> Phosphorus (P)
Phosphorus is the 15th element of the periodic table. The number of electrons in phosphorus atom are 15.
The electronic configuration of phosphorus is 
- <u>Option c:</u> Vanadium (V)
Vanadium is the 23rd element of the periodic table. The number of electrons in vanadium atom are 23.
The electronic configuration of vanadium is 
- <u>Option d:</u> Antimony (Sb)
Antimony is the 51st element of the periodic table. The number of electrons in antimony atom are 51.
The electronic configuration of antimony is 
- <u>Option e:</u> Samarium (Sm)
Samarium is the 62nd element of the periodic table. The number of electrons in samarium atom are 62.
The electronic configuration of samarium is 
Hence, the electronic configuration of the elements are written above.
Answer:
Independent Variable: Grade Level
Dependent Variable: Growth in height
Hypothesis: Students in [Insert the grade level you believe will grow the quickest here] will experience the quickest growth in height.
Explanation:
Independent variables are the factors in which you manipulate to gain your results, in this case you would be changing the grade level you would observe to see the height.
Dependent variables are the factors that respond to changes in the independent variables. You don't control these events, you simply observe them. In this case, you merely observe the growth in height in accordance to the different grade levels you observe.
For the hypothesis, you would create your own hypothesis based on a guess you have. You create a hypothesis not based on the data, but on what you believe will be correct before doing the experiment. It doesn't have to be the correct answer, but just your thoughts.