Which tool was most likely used in a procedure if the lab report shows 300ml of water was used

Select the correct answer.

Xelga [282]

Lead (II) chloride+ potassium nitrate
PbCI2+KNO3(B)

6 0

2 years ago

A compound is 44.7% P and the rest O. Determine its emperical formula.

svet-max [94.6K]

Answer:

P₅O₁₂

Explanation:

Assume that you have 100 g of the compound.

Then you have 44.7 g P and 55.3 g O.

1. Calculate the moles of each atom

Moles of P = 44.7 × 1/30.97 = 1.443 mol Al

Moles of O = 55.3 × 1/16.00 = 3.456 mol O

2. Calculate the molar ratios.

P: 1.443/1.443 = 1

O: 3.456/1.443 = 2.395

3. Multiply by a number to make the ratio close to an integer

P: 5 × 1 = 5

O: 5 × 2.395 = 11.97

3. Determine the empirical formula

Round off all numbers to the closest integer.

P: 5

O: 12

The empirical formula is P₅O₁₂.

6 0

3 years ago

Do you think thermal expansion affects all states of matter or just the solid? Explain your thinking.

torisob [31]

Answer:

All three states of matter (solid, liquid and gas) expand when heated. The atoms themselves do not expand, but the volume they take up does.

When a solid is heated, its atoms vibrate faster about their fixed points. The relative increase in the size of solids when heated is therefore small. Metal railway tracks have small gaps so that when the sun heats them, the tracks expand into these gaps and don’t buckle.

Liquids expand for the same reason, but because the bonds between separate molecules are usually less tight they expand more than solids. This is the principle behind liquid-in-glass thermometers. An increase in temperature results in the expansion of the liquid which means it rises up the glass.

Molecules within gases are further apart and weakly attracted to each other. Heat causes the molecules to move faster, (heat energy is converted to kinetic energy) which means that the volume of a gas increases more than the volume of a solid or liquid.

However, gases that are contained in a fixed volume cannot expand - and so increases in temperature result in increases in pressure.:

5 0

2 years ago

What mass of sucrose (C12H22O11) should be combined with 546 g of water to make a solution with an osmotic pressure of 8.80 atm

lesya [120]

Answer: The mass of sucrose required is 69.08 g

Explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

$\pi=iMRT$

Or,

$\pi=i\times \frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}\times RT$

where,

$\pi$ = osmotic pressure of the solution = 8.80 atm

i = Van't hoff factor = 1 (for non-electrolytes)

Mass of solute (sucrose) = ?

Molar mass of sucrose = 342.3 g/mol

Volume of solution = 564 mL (Density of water = 1 g/mL)

R = Gas constant = $0.0821\text{ L.atm }mol^{-1}K^{-1}$

T = Temperature of the solution = 290 K

Putting values in above equation, we get:

$8.80atm=1\times \frac{\text{Mass of sucrose}\times 1000}{342.3\times 546}\times 0.0821\text{ L.atm }mol^{-1}K^{-1}\times 290K\\\\\text{Mass of sucrose}=\frac{8.80\times 342.3\times 546}{1\times 1000\times 0.0821\times 290}=69.08g$

Hence, the mass of sucrose required is 69.08 g

5 0

2 years ago

During a science investigation, a sample of matter breaks down into two kinds of atoms. Was the original sample an element or a

nevsk [136]

The original sample was a compound because it was composed of two different elements and was not purely one element

3 0

2 years ago