Because The bar would become negatively charged and repel the metal ball. A magnetic north pole would be generated on the bar, and it would repel the metal ball.
Answer:
Explanation:
Li(s)+1/2 F₂(g)→LiF(s)
In this reaction one mole of product is formed from gaseous state of reactants . So this reaction will represent the reaction for which ΔH∘rxn equals to ΔH∘f .
In other reaction one mole is not produced if we balance the reaction. The reactant must be in gaseous state . ΔH∘f . represents heat of formation . ΔH∘rxn represents heat of reaction .
Hi my dear friend,
Because we must add heat, boiling water is a process that chemists call endothermic. Clearly, if some processes require heat, others must give off heat when they take place. ... Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.
~Thank you
Answer:
pKa = 3.51
Explanation:
The titration of acid solution with NaOH can be illustrated as:
Given that:
Volume of acid solution 
Volume of NaOH 
Molarity of acid solution 
Molarity of NaOH 
For Neutralization reaction:
Making 
the subject of the formula; we have:
However; since the number of moles of NaA formed is equal to the number of moles of NaOH used : Then :
Total Volume after titration = ( 25 + 18.8 ) m
= 43.8 mL
Molarity of salt (NaA ) solution = 
= 
= 0.0429 M
After mixing the two solution ; the volume of half neutralize solution is = 25 mL + 43.8 mL
= 68.8 mL
Molarity of NaA before mixing 
Volume 
Molarity of NaA after mixing 
Volume 
∴
Molarity of acid before mixing = 0.0725 M
Volume = 25 mL
Molarity of acid after mixing = 
= 0.0273 M
Since this is a buffer solution ; then using Henderson Hasselbalch Equation
![pH = pKa + log \frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pH%20%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
![3.51= pKa + log \frac{[0.0273]}{[0.0273]} \\ \\ 3.51= pKa + log \ 1 \\ \\ 3.51= pKa + 0 \\ \\ pKa = 3.51](https://tex.z-dn.net/?f=3.51%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5B0.0273%5D%7D%7B%5B0.0273%5D%7D%20%5C%5C%20%20%5C%5C%203.51%3D%20pKa%20%2B%20log%20%5C%201%20%20%5C%5C%20%5C%5C%203.51%3D%20pKa%20%2B%200%20%5C%5C%20%5C%5C%20pKa%20%3D%203.51)
Inside the ground, different types of rocks and minerals are pressed together. The pressure causes the rocks to go together and form the sediments. Examples of sedimentary rocks are: sandstone, siltstone, and shale.
