Answer:
Dissolving sugar in water, burning paper, and melting gold are all chemical changes
Explanation:
The action cannot be reversed, or undone. Therefore it is a chemical change.
Boiling water is a physical change.
Answer:
See Explanation
Explanation:
Let us consider the first two reactions, the initial concentration of CO was held constant and the concentration of Hbn was doubled.
2.68 * 10^-3/1.34 * 10^-3 = 6.24 * 10^-4/3.12 * 10^-4
2^1 = 2^1
The rate of reaction is first order with respect to Hbn
Let us consider the third and fourth reactions. The concentration of Hbn is held constant and that of CO was tripled.
1.5 * 10^-3/5 * 10^-4 = 1.872 * 10^-3/6.24 * 10^-4
3^1 = 3^1
The reaction is also first order with respect to CO
b) The overall order of reaction is 1 + 1=2
c) The rate equation is;
Rate = k [CO] [Hbn]
d) 3.12 * 10^-4 = k [5 * 10^-4] [1.34 * 10^-3]
k = 3.12 * 10^-4 /[5 * 10^-4] [1.34 * 10^-3]
k = 3.12 * 10^-4/6.7 * 10^-7
k = 4.7 * 10^2 mmol-1 L s-1
e) The reaction occurs in one step because;
1) The rate law agrees with the experimental data.
2) The sum of the order of reaction of each specie in the rate law gives the overall order of reaction.
The balanced chemical reaction is:
N2 + 3H2 = 2NH3
We are given the amount of ammonia formed
from the reaction. This is where we start our calculations.
0.575 g NH3 (1 mol NH3 / 17.03 g NH3) (3 mol
H2 / 2 mol NH3) ( 2.02 g H2 / 1 mol H2) = 0.10 g H2
Answer:
Explanation:
The standard system of measurement is what is popularly referred to as SI unit (or international system of units). For example, the SI unit for length is basically in meters (m), which is convertible to millimeter (mm), centimeter (cm) or even kilometer (km).
If there is no standard system of measurement,
1) Scientists will not be able to compare data as every scientist will use a unit that suits him/herself which might make data incomparable as some units might be difficult to convert to other units or there conversion methods might even be debatable.
2) There might be a general lack of understanding of the research work done by a scientist/scientists in the scientific community. This is because the standard system of measurement affords scientists to communicate properly with the same or convertible units and based on 1. above, if scientists use any unit that isn't agreed upon, different/unknown/debatable units might make understanding of research works incomprehensible.
Answer: The number of moles of excess reagent remain unreacted will be, 6.004 moles.
Explanation : Given,
Moles of 
= 1.332 mol
Mass of 
= 6.504 mol
First we have to calculate the limiting and excess reagent.
The balanced chemical equation is:
From the balanced reaction we conclude that
As, 13 mole of react with 1 mole of
So, 6.504 moles of react with 
moles of
From this we conclude that, is an excess reagent because the given moles are greater than the required moles and is a limiting reagent and it limits the formation of product.
Number of moles remain unreacted = 6.504 mol - 0.5003 mol = 6.004 mol
Therefore, the number of moles of excess reagent remain unreacted will be, 6.004 moles.
