The temperature stays the same when a solid changes to a liquid because energy is required to break the forces between particles of water therefore changing the state of matter and separating the particles away from each other.
When a liquid boils, the energy is needed by the particles to escape the surface of the liquid and boil. Instead of raising the temperature, the energy goes into the particles' kinetic energy store so it has enough speed to escape the surface of the liquid.
Answer:
A.
Explanation:
A) The number of H+ ions in the substance is equal to the number of OH-ions.
12 % salt is present in 125 g mixture of salt and sand.
Keep in mind that the total percentage is always 100 %
Therefore, if 12 % is the salt, remaining 88 % must be
sand.
a. The amount of mixture is 125 q. Here, 12 % of 125 is
12 * 125 / 100 = 15 g of salt is present in 125 g mixture.
b. The amount of sand can be calculated similarly, 88 %
of 125 g is 88 * 125 / 100 = 110 g of sand is present in
125 g mixture.
Answer:
128.4 m
Explanation:
3.604m + 104.29m + 3.1m + 17.41m
Add all the values
= 128.404 m
The significant figure rule for addition is for the sum to have the same number of decimal places as the value with the least number of decimal places. In the addition sentence 3.604m + 104.29m + 3.1m + 17.41m, the value with the least number of decimal places is 3.1, which has 1 decimal place. Therefore, we round our sum so that it also has 1 decimal place.
128.404 m
= 128.4 m
I hope this helps!
1) since we are given percentages, we can assume we have 100 grams of the molecule.
55.6 % Cu ----> 55.6 grams Cu
16.4 % Fe------> 16.4 grams Fe
28.0% S--------> 28.0 grams S
2) convert each gram to moles using the molar masses given
3) we divide the smallest value of moles (0.293) to each one.
Cu --> 0.876 / 0.293= 3
Fe---> 0.293 / 0.293= 1
S-----> 0.875 / 0.293= 3
4) let's write the empirical formula
Cu₃FeS₃
