Sometimes light behaves like a wave, and sometimes it behaves like a particle. True False

Elements with similar properties [A] sodium and bromine [B] lithium and sodium [C] carbon and oxygen [D] potassium and helium

Shkiper50 [21]

Usually, elements which share the same group, they have similar properties, here only Lithium and sodium share same group as they both are alkali metals.

So, In short, Your Answer would be option B) Lithium and Sodium

Hope this helps!

8 0

3 years ago

If a concentrated solution of acetic acid is 99.5 % HC2 H3 O2 and has a density of 1.05 g/mL, what is the concentration of this

cluponka [151]

Answer:

[CH₃COOH] = 17.4 M

Explanation:

Acetic acid → CH₃COOH

Molar mass → 60 g/mol

99.5% is percent by mass concentration. It means that 99.5 grams of solute are contained in 100g of solution.

Density → 1.05 g/mL. This data is always referred to solution, not solute!.

We determine solution's volume:

1.05 g/mL = 100 g / V → V = 100 g /1.05 g/mL → 95.2 mL

Now we know, that 99.5 g of acetic acid are contained in 95.2 mL

Let's convert to mmoles → 99.5 g / 60 g/mol = 1.66 moles

We convert solution's volume to L → 95.2 mL . 1L / 1000 mL = 0.0952 L

M (mol/L) = 1.66 mol / 0.0952 L = 17.4 M

5 0

3 years ago

50cm3 of sodium hydroxide solution was titrated against a solution of sulfuric acid. The concentration of the sodium hydroxide s

miskamm [114]

Answer:

49 g/L is the concentration of the acid

Explanation:

Firstly, we proceed to write the equation of reaction.

2NaOH + H2SO4 ——-> Na2SO4 + 2H2O

We can see that 1 mole of the base reacted with two moles of the acid.

kindly note that dm^3 is same as liter

Firstly, we need to get the concentration of the reacted sulphuric acid in g/L

we use the simple titration equation below;

CaVa/CbVb = Na/Nb

From the question;

Ca = ?

Va = 25 cm^3

Cb = 20 g/L

we convert this to concentration in mol/L

Mathematically, that is concentration in g/L divided by molar mass in g/mole

molar mass of NaOH = 40 g/mol

so we have; 20g/L / 40 = 0.5 mol/L

Vb = 50 cm^3

Na = 1

Nb = 2

Where C represents concentrations, V volumes and N , number of moles

Now, substitute the values;

Ca * 25/0.5 * 50 = 1/2

25Ca/25 = 0.5

So Ca = 0.5 mol/L

Now to get the concentration of H2SO4 in g/L

What we do is to multiply the concentration in mol/L by molar mass in g/mol

That would be 0.5 * 98 = 49 g/L

4 0

4 years ago

Which mineral property is easily observed but can be unreliable when it comes to mineral identification

patriot [66]

I believe it is the color

7 0

3 years ago

PLS HELP ME WILL GIVE BRAIN THINGYYYYY

alexandr1967 [171]

Answer:

C, when the ball lands it will have the least amount potential energy.

Explanation:

here is a picture that should help you.

6 0

3 years ago