<span>The number of valence electrons. :) have a good day </span>
Answer:
3.269 kg
Explanation:
1000g = 1 kg. Since kg is the larger unit, you need to divide by 1000 to get kilograms. You can do the problem as a unit conversion:
3269 g × <u>1 kg</u> = 3.269 kg
1000g
Hope this is helpful!
Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
Root mean square velocity is the square root of the mean of the squares of speeds of different molecules. From kinetic theory of gas, the formula of root mean square velocity=C
= √
=√
=√
, where, R= Universal gas constant, T= Absolute temperature, P= Pressure, V= Volume of gas, d= Density of gas.
Given, T=273 K, P=1.00 x 10⁻² atm, d=1.24 x 10⁻⁵ g/cm³.
(a) Using the formula 
=√=√(3X1.00X10⁻²)/(1.24X10⁻⁵)=49.18
(b) Molar mass can be determined by using the formula =√{3RT}{M}
49.18=√
49.18²=√(3X8.314X273)/M
M=
M=1.67 ≅ 2
Molecular mass is 2.
(c) The gas is Helium (He) whose molecular mass is 2.
