Answer:
17. The iron metal is oxidized to form the iron oxide known as rust.
19.A saturated solution will not dissolve any more solute and any extra solute added will simply stay as it is, without dissolving. An unsaturated solution has less solute than its solubility and hence can still add more solute, till it reaches the saturation level.
26 An Overflowing Population. The swelling American population played a large part in the decision Americans made to head, The Government Opens Up New Land. The American government itself encouraged its citizens to move west
32. The periodic table was first assembled in 1869 by a Russian chemist named Dmitri Mendeleev. He came up with a way of organizing the elements that were known at the time, arranged them in order of atomic weight, and then grouped them into rows and columns based on their chemical and physical properties. Here is a unique "Mayan" format Periodic Table. Elements in the same group are those that are in a single vertical line from top to bottom. They have the most in common between the two directions. They share the same number of electrons in their valence subshells.
Explanation:
Answer:
Option (1) Br– is the catalyst, and the reaction follows a faster pathway with Br– than without
Explanation:
Let us consider the equation below:
Step 1:
H2O2(aq) + Br–(aq) → H2O(l) + BrO–(aq)
Step 2:
BrO–(aq) + H2O2(aq) → H2O(l) + O2(g) + Br–(aq)
From the above equation, we can see that Br– is unchanged.
This implies that Br– is the catalyst as catalyst does not take part in a chemical reaction but they create an alternate pathway to lower the activation energy in order for the reaction to proceed at a much faster rate to arrive at the products.
Answer:
Option (D) freezing point depression
Explanation:
Calcium chloride is added to the roadways after a snowstorm because it reduces the freezing point of the ice. Further more, it has been observed that the calcium chloride also produces enough heat which enhances the melting of the ice as it produces an exothermic reaction.
Answer:
63.53% yield
Explanation:
The balanced equation for this reaction is 2NaCl + H2O -> 2NaOH +Cl2
First we must find the limiting reactant
From NaCl we can only produce 6.06 grams of Cl2 in <u>theory</u>
From H20 we can only produce 38.995 grams in theory
so we know NaCl is the limiting
% yield is (Actual/Theoretical) x100 so
(3.85/6.06)x100= 63.53% yield
The period number of krypton is 4
