The answer is
D) an ice cube
Answer:
The answer to your question is below
Explanation:
1. Found in period 2. All the elements in the list are found in period 2.
a. F This option is correct
b. Be Beryllium is located in period two.
c. O also oxygen is found in period 2.
d. C Carbon is found in period 2.
2.- Can gain lose 4 electrons to become its nearest stable noble gas. Only Carbon.
a. F This option is wrong, F becomes stable when it gains 1 electron.
b. Be Beryllium becomes stable when it loses 2 electrons.
c. O Become stable when it gains 2 electrons.
<u>d. C </u><u>Become stable when it gains or loses 4 electrons.</u>
1.) A compound is a thing that is composed of two or more (separate) elements.
2.) A compound cannot be separated easily, while its properties differ from where it originates from. It also is formed from chemical reactions.
3.) A pure substance, also known as chemical substance, is a material with constant composition and consistant properties.
4.) If a substance is not a pure substance, then it is an impure substance.
Hope this helped. :)
ANSWER: True
EXPLANATION: An inference is a logical conclusion based on observations.
Hope it helps u!
Explanation:
Given:
Ka = 1.8 × 10-4
HCOOH --> HCOO- + H+
HA --> H+ + A-
Ka = [H+] × [A-]/[HA]
[HA] = 0.12 M
[H+] = [A-] = x^2
1.8 × 10^-4 × 0.12 = x^2
x = 0.00465 M
pH = - log [H+]
= -log [0.00465]
= 2.33
B.
Since 1 mole of NaOH reactes with 1 mole of HCOOH.
Number of moles of NaOH = 0.08 × 15 × 10^-3
= 0.0012 mole.
Concentration of HCOOH = 0.0012/20 × 10^-3
= 0.06 M
[HA] = 0.06 M
1.8 × 10^-4 × 0.06 = x^2
x = 0.00329 M
pH = - log [H+]
= -log [0.00329]
= 2.48
C.
Since 1 mole of NaOH reacts with 1 mole of HCOOH.
Number of moles of NaOH = 0.08 × 30 × 10^-3
= 0.0024 mole.
Concentration of HCOOH = 0.0024/20 × 10^-3
= 0.12 M
[HA] = 0.12 M
1.8 × 10^-4 × 0.12 = x^2
x = 0.00465 M
pH = - log [H+]
= -log [0.00465]
= 2.33
D.
Since 1 mole of NaOH reactes with 1 mole of HCOOH.
Number of moles of NaOH = 0.08 × 30.5 × 10^-3
= 0.00244 mole.
Concentration of HCOOH = 0.00244/20 × 10^-3
= 0.122 M
[HA] = 0.122 M
1.8 × 10^-4 × 0.122 = x^2
x = 0.00469 M
pH = - log [H+]
= -log [0.00469]
= 2.33
