Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:

.90 dL is 90 mL because 1 dL is 100 mL
Answer:
The correct answer is Sugar has a greater solubility than sand.
Sugar will easily dissolve in water because it has a lower density than sand, therefore it has a greater solubility.
Answer: Most of them lie in a belt between Earth and Mars.
Explanation:
Asteroids are small rocky bodies having irregular shape size which orbit sun. Majority of the asteroids are found in a belt between orbits of Mars and Jupiter. Scientists presume that these asteroids are remains of a planet that never formed between Mars and Jupiter due to great gravitational pull of the largest planet of the solar -system - Jupiter.
Thus, the incorrect description of the asteroids is: Most of them lie in a belt between Earth and Mars.
Answer:
P2≈393.609Kpa so I think the answer is 394 kPa
Explanation:
PV=mRT Ideal Gas Law
m and R are constant because they dont change for the problem. That means
PV/T=mR = constant
so P1*V1/T1=P2*V2/T2 and note that the temperatures are in absolute temperatures (Kelvin) because you can't divide by zero.
So P2 = P1*V1*T2/(V2*T1) = 101325 Pa * 700 mL * 303K/(200 mL*273K)
P2 = 393609 Pa