Answer:
A) litmus is red
Explanation:
To answer this question, it can be helpful to have the color charts. Litmus, phenolphthalein and methyl orange are ways to test the pH of a substance.
<u>Litmus paper</u>
Litmus can tell you if a substance is an acid or a base. You need to put the substance on both red litmus and blue litmus paper.
pH < 7: both papers are red. 3.0 is less than 7.
pH = 7: none of them change color
pH > 7: both papers are blue
<u>Phenolphthalein</u>
When this indicator is added to a substance, the result is either colorless or pink.
0 < pH ≤ 7: colorless. The color is not red or blue for pH 3.0.
pH > 7: pink
<u>Methyl orange</u>
0 < pH < 4: red. The color is not yellow if the pH is 3.0.
4 ≤ pH < 5: orange
pH ≥ 5: yellow
The Alkali Metals- (Group 1A)can be found (excluding hydrogen) in the first column of the periodic table. They all have 1 valence electron and tend to form +1 cations when forming Ionic bonds with non metals.
The Alkali Earth Metals: (Group 2A) can be found in the second column/group on the periodic table. These elements form +2 positively charged cations when forming Ionic bonds with non metals. They also all have 2 valence electrons.
The Halogens: are the elements that make up the second to last group on the periodic table. These elements include Chlorine, Fluorine, Bromine, Iodine, and Astatine. These elements have 7 valence electrons. The usually form a -1 charged anion when forming ionic bonds with metals.
The Noble gases: the very last group on the periodic table. All these elements have 8 valance electrons. Due to the octet rule these atoms are already very stable and rarely react with other elements.
Answer is: molar mass
of compound is 154,58 g/mol.<span>
m(</span>naphthalene<span>) = 10 g = 0,01 kg.
m(unknown compound) = 1,00 g.
</span>Δ<span>T (solution) = 4,47 °C.
Kf(</span>naphthalene) = 6,91°C/m<span>; cryoscopic
constant.
M</span>(unknown compound) = Kf(naphthalene)· m(unknown compound) ÷
m(naphthalene)<span> · ΔT(solution).
M(xylene) = </span>6,91°C/m<span> · 1 g ÷ 0,01 kg · 4,47</span>°C<span>.
M(xylene) = 154,58 g/mol.</span>
Answer:
Bohr diagram shows electrons orbiting the nucleus. Nitrogen has 7 electrons orbiting the nucleus
Lewis structure is the simplified Bohr diagram. It only shows the electrons in the outer shell. For Nitrogen, 2 electrons are in the first shell. The remaining 5 electrons are in the outer shell.
Explanation:
Bohr diagram shows electrons orbiting the nucleus. Nitrogen has 7 electrons orbiting the nucleus
Lewis structure is the simplified Bohr diagram. It only shows the electrons in the outer shell. For Nitrogen, 2 electrons are in the first shell. The remaining 5 electrons are in the outer shell.
Answer:
The molar concentration would have to be 0,81 M.
Explanation:
The osmotic pressure equation is:
where:
: osmotic pressure [atm]
M: molar concentration [M]
R: gas constant 0,08205 [atm.L/mol.°K]
T: absolute temperature [°K]
To solve the problem, we just clear M from the osmotic pressure equation and then replace our data using the appropiate units. Clearing the variable M we have:
We have to use temperature as absolute temperature (in kelvins), T=29+273=302 °K. Now we can replace our values in the equation:
As we can see, all units will be simplified and we'll have the molar concentration in mol/L.
