Answer:
Adding or removing energy from matter causes a physical change as matter moves from one state to another. For example, adding thermal energy (heat) to liquid water causes it to become steam or vapor (a gas). And removing energy from liquid water causes it to become ice (a solid).
948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
The answer would be b, or 2
Answer:
CH3 - CH2 - NH - C(CH3)3
Explanation:
The 1HNMR is the acronym for Proton nuclear magnetic resonance and it is used in chemistry or Chemical laboratory for the analysis and identification of compounds.
In order to be able to answer the question accurately you have to have the tables containing all the values for chemical shift. The Chemical shift is measured in ppm and it occur due to Resonance frequency variation.
From the table, a singlet at 1.15 ppm (9H) is - C(CH3)3.
A singlet at d 0.9 ppm (1H) shows the presence of a secondary amine group, that is -R2NH group.
A triplet at 1.10 ppm (3H) shows that we have;
CH3- CH2-
A quartet at 2.6 ppm (2H) shows that we have;
-CH2 - CH3.
Therefore, joining all together we have;
CH3 - CH2 - NH - C(CH3)3.
Kindly check attached file for the picture of the structure.
