Answer:
Mass Number
Explanation:
In nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.
Please vote brainliest!
Answer:
When chromium chloride, CrCl2, is dissolved in water, the temperature of the water decreases. ... The attractive forces between water molecules and chromium and chloride ions is stronger, because the reaction is endothermic means the energy released in formation is less than the energy required in breaking bond.
Answer:
a) 1,6%
b) 64,775 g/mol
c) 3,6×10⁻² M
d) 2,3×10⁻³ g/mL
Explanation:
a) The mass fractium of helium is obtained converting the moles of the four gases to grams with molar weight and then caculating of the total of grams how many are of helium, thus:
- Helium: 0,25 moles × = 1 g of Helium
- Argon: 0,25 moles × = 10 g of Argon
- Krypton: 0,25 moles × = 20,95 g of krypton
- Xenon: 0,25 moles × = 32,825 g of Xenon
Total grams: 1g+10g+20,85g+30,825g= 62,675 g
Mass fraction of helium: × 100 = <em>1,6%</em>
<em />
<em>The mass fraction of Helium is 1,6%</em>
<em />
<em>b)</em><em> </em>Because the mole fraction of all gases is the same the average molecular weight of the mixture is:
= 64,775 g/mol
c) The molar concentration is possible to know ussing ideal gas law, thus:
= M
Where:
P is pressure: 150 kPa
R is gas constant: 8,3145
T is temperature: 500 K
And M is molar concentration. Replacing:
M = 3,6×10⁻² M
d) The mass density is possible to know converting the moles of molarity to grams with average molecular weight and liters to mililiters, thus:
3,6×10⁻² × × =
2,3×10⁻³ g/mL
I hope it helps!
A. 1 valence electron
b. 4 valence electrons
c. 2 valence electrons
d. 6 valence electrons
Answer:
The pressure will be 0,37 atm.
Explanation:
We use the Boyle Mariotte´s formula,where for a given mass of gas, at constant temperature, the pressure and temperature vary inversely proportionally. We see here that the initial and final temperature does not vary (298K).
We convert the unit Celsius into Kelvin (0 ° C = 273K) and the unite mmHg into atm (760mmHg=1 atm):
25°C= 25+273=298K ; (1060mmHgx 1 atm)/760mmHg)=1,39 atm.
We convert unit of volume from ml to L: 174/1000=0,174L and 650/1000=0,650L
P1xV1= P2xV2
1,39 atm x 0,174L =P2 x0,650L
P2= (1,39 atm x 0,174L)/0,650L= 0,37 atm