Answer:
1. Density can be used to identify a substance
2. Density can be used to ascertain whether a substance will float in water.
Explanation:
The calculation of the density of a substance can be used to identify the substance. If the density of a substance is calculated accurately, and compared with a table of standard densities, then we can identify that substance.
Also, density determines whether an object will float or sink in water. If an object is less dense than water then it will float in water. If it is denser than water, then it will sink in water.
Answer:
The pH changes by 2.0 if the [A-]/[HA] ratio of a base/weak acid mixture changes from 10/1 to 1/10.
Explanation:
To solve this problem we use the<em> Henderson-Hasselbach equation</em>:
Let's say we have a weak acid whose pKa is 7.0:
If the [A⁻]/[HA] ratio is 10/1, we're left with:
Now if the ratio is 1/10:
The difference in pH from one case to the other is (8.0-6.0) 2.0.
<em>So the pH changes by 2.0</em> if the [A-]/[HA] ratio of a base/weak acid mixture changes from 10/1 to 1/10.
<u>Keep in mind that no matter the value of pKa, the answer to this question will be the same.</u>
El hidrógeno es el elemento químico de número atómico 1, representado por el símbolo H. Con una masa atómica de 1.00784 u es el más ligero de la tabla periódica de los elementos. Por lo general, se presenta en su forma molecular, formando el gas diatómico H₂ en condiciones normales.
Answer: I am pretty sure it is E
Explanation:
10 miles per hour because 500 divided by 50 is 10
