There are 1.923×10^23 formula units in 30.4g mgcl2
molar mass of mgcl2= 95.211g/mol
magnesium= 24.305g/mol
chlorine= 35.45g/mol times 2
24.305+(35.45*2)= 95.211g/mol
sample divided by molar mass times Avogadro's number gives u the formula units
30.4÷ 95.211= .31929
.3193*6.022=1.9288
<span>Part of a rocket's propulsion system includes a chemical oxidizer, either in the form of liquid oxygen, the solid ammonium perchlorate, or the propulsion/oxidizer mixture Hydrazine. No outside source of oxygen is needed.
Steering is accomplished by "gimbaled" rocket nozzles which change the direction of the blast to keep the rocket on course. Once in space and in orbit, slight changes in orientation is made by small rockets placed around the craft that spurt little gas jets to nudge the craft into the desired position.</span><span>
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<span>the change in entropy is positive and change in enthalpy is negative.and potential energy is lower.and the reason is materials in nature naturaly want to get stabler and more chaotic.
for the second question there is a big formula.Equilibrium θ=mcθ1(water)+mcθ1(metal) /mc(water)+mc(metal) just put numbers and it is easy to solve.equlibrium temperture is 23.5</span>