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3 years ago

PLSSSSS HELPPPP......

Chemistry

1 answer:

rosijanka [135]3 years ago

7 0

Answer: A

Explanation:
The buoyancy force only takes affect when an object is placed in water and floats. This occurs because the density of that object is less than the density of water.
Water is the main liquid used for measuring the density of an object.

Hope this helps! Please tell me if I am wrong :3

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Give examples to three solutions you commonly use and identify the solvent and solutes that make it each up.

8_murik_8 [283]

Mouthwash:
solvent - water
solute - alcohols

vinegar:
solvent - water
solute - acetic acid

bleach:
solvent - water
solute - sodium hypochlorite

hope this helps!!

8 0

3 years ago

Read 2 more answers

If an atom has three shell and number of valence electrons are two. Is this element metal

cluponka [151]

Answer:

Metal

Element: Calcium

Valency: 2

Explanation:

To find the element, let's use the periodic table. (Look below)

We already went past 3 shells, just need the 2 electrons after it.

Just skip to the 4th row and count 2 to the right

We end up at Calcium.

Calcium is a metal and we're also on the alkaline earth metals column.

Calcium will need to lose 2 electrons to reach stability, so the valency is 2.

3 0

3 years ago

A certain substance X has a normal freezing point of -6.4 C and a molal freezing point depression constant Kf= 3.96 degrees C.kg

Brut [27]

Answer: $1.0\times 10^2g$

Explanation:

Depression in freezing point is given by:

$\Delta T_f=i\times K_f\times m$

$\Delta T_f=T_f^0-T_f=(-6.4-(13.6))^0C=7.2^0C$ = Depression in freezing point

i= vant hoff factor = 1 (for non electrolyte like urea)

$K_f$ = freezing point constant = $3.96^0C/m$

m= molality

$\Delta T_f=i\times K_f\times \frac{\text{mass of solute}}{\text{molar mass of solute}}\times \text{weight of solvent in kg}}$

Weight of solvent (X)= 950 g = 0.95 kg

Molar mass of non electrolyte (urea) = 60.06 g/mol

Mass of non electrolyte (urea) added = ?

$7.2=1\times 3.96\times \frac{xg}{60.06 g/mol\times 0.95kg}$

$x=1.0\times 10^2g$

Thus $1.0\times 10^2g$ urea was dissolved.

8 0

3 years ago

A full bottle of water was left outside overnight in freezing temperatures, causing the bottle to crack. No mass was added or re

kodGreya [7K]

Answer:The correct answer is option C.

Explanation;

Water has unique property that is, it expands on freezing.Which is the reason for less density of ice than water. The cracking of the bottle was due to the expansion of water (present inside the bottle) on freezing.

Generally, density is inversely proportional to the volume of the substance.

$Density=\frac{Mass}{Volume}$

$Density\propto \frac{1}{Volume}$

As we know ,that water expands on freezing which means that volume increases. And with increase in volume of density decreases.

Hence, the correct answer is option C.

6 0

3 years ago

Would precipitation occur when 500 mL of a 0.02M solution of AgNO3 is mixed with 500 mL of a 0.001M solution of NaCl? Show your

Oksanka [162]

We know,
AgNO3 + NaCl ⇒ NaNO3 + AgCl(s)
The moles of Na+ present:
0.5 L * 0.001 mol/L
= 5 x 10⁻⁴ mol
Moles of Ag+ present:
0.5 * 0.02
= 0.01 mol
The limiting reactant is Na
Therefore, the moles of Ag reacted:
5 x 10⁻⁴
AgCl is insoluble in water; therefore, the AgCl formed will precipitate

7 0

3 years ago