Answer:
nếu có 40g dung dịch NaOH 20% phairn dùng hết bao nhiêu gam dung dịch HCl 25% để trung hoà
Answer:
C6H6
Explanation:
We can obtain the molecular formula from the empirical formula.
What we need do here is:
(CH)n = 78
The n shows the multiples of both element present in the actual compound. It can be seen that carbon and hydrogen have the same element ratio here. We then use the atomic masses of both elements to get the value of n. The atomic mass of carbon is 12 a.m.u while the atomic mass of hydrogen is 1 a.m.u
(1 + 12)n = 78
13n = 78
n = 78/13 = 6
The molecular formula is
(CH)n = (CH)6 = C6H6
Answer:
snail should be at the top
Explanation:
The household substances that will turn blue litmus paper red are: A) bleach and D) Vinegar. This is because bleach contains acidic solutions; and vinegar contains a percentage of organic acids for example, acetic acid.
Physical properties help identifying a substance and how it changes.
For example: if a substance crushes easily that means it has a low density, but if it’s hard and doesn’t crush easily, that means it has a strong high density.
And eventually the substance would not end up forming a new substance.
Look at the picture below to understand more about physical changes.