Answer:
=0.475M
Explanation:
Molarity=(moles of solute))/(litres of solution)
So, molarity in this question:
=(0.19 moles of sodium carbonate)/(0.4 L of solution)
=0.475M
~Hope this helps:)
Answer:
P₂ = 1.37
Explanation:
Given data:
Initial pressure = 1.15 atm
Initial temperature = 23°C (23+273= 296 K)
Final pressure = ?
Final temperature = 79°C (79+273=352 K)
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
1.15 atm / 296 K = P₂/352 K
P₂ = 1.15 atm × 352 K / 296 K
P₂ = 404.8 atm. K /296 K
P₂ = 1.37 atm
B. It is open to change as new evidence or data is discovered. If scientists discover new evidence, they must modify their theories to conform with the new data.
A. is <em>incorrect</em>. Scientific laws are so well established that there can be no exceptions.
C. is <em>incorrect</em>. A scientific theory is the collective judgement of scientists as to the best explanation for a phenomenon. A new observation may require modification of the theory.
D. is <em>incorrect</em>. Advancements in technology can provide new evidence that requires new explanations.
if the product has lesser energy than the reactants it means enthalpy change value is positive.so it is endothermic reaction where the heat is absorbed.so kcl will formation will have positive enthalpy change .
