What is the total number of joules required to freeze a 10 g sample of water at 0°C?

Why are groups 1 and 2 referred to as the s-block of the periodic table

qwelly [4]

Answer: This is because their valence electrons are located in the S - orbital

Explanation:

This is because their valence electrons are located in the S - orbital.

3 0

3 years ago

A student mixed a small amount of iron filings and sulphur powder in a dish. He could not

Temka [501]

Answer:

$\huge \boxed{\mathrm{Carbon \ disulphide}}$

Explanation:

Carbon disulphide is the liquid that can be used to separate iron fillings and sulphur powder.

When carbon disulphide is poured into the dish, the sulphur powder gets easily dissolved in the carbon disulfide. The iron fillings are left to settle on the bottom of the dish.

The iron fillings can get seperated through filtration. When the mixture of sulphur powder and carbon disulphide gets completely evaporated, the sulphur powder is left over.

7 0

3 years ago

(a) calculate the molarity of a solution made by dissolving 0.0815 mol na2so4 in enough water to form exactly 550. ml of solutio

Vesna [10]

You just need to convert it into moles per Liter (mol/L).

0.0815mol / 0.550L = 0.148mol/L

4 0

3 years ago

The density of mercury is 13.5g/mL. What is the volume of this liquid if the sample weighs 12.5 pounds?

Mama L [17]

Answer : The volume of liquid is 420 mL.

Explanation :

Density : The mass per unit volume of a substance is known as density.

Formula used:

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

As we are given:

Density of mercury = 13.5 g/mL

Mass = 12.5 pounds

First we have to convert mass of sample from pound to gram.

Conversion used:

As, 1 pound = 453.6 g

So, 12.5 pounds = 453.6 × 12.5 g = 5670 g

Now we have to calculate the volume of liquid.

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

Now putting all the given values in this formula, we get:

$13.5g/mL=\frac{5670g}{\text{Volume}}$

Volume = 420 mL

Therefore, the volume of liquid is 420 mL.

7 0

3 years ago

A rotameter calibration curve (flow rate versus float position) obtained using a liquid is mistakenly used to measure a gas flow

Veronika [31]

Answer:

I would expect the gas rate determined in this manner to be too low

Explanation:

A Rotameter can be designed to respond to the sensitivity of density, velocity, to measure the flow rate of liquid or gas enclosed in a tube. Liquids are denser than gas, and since the gas rate to be determined needed to respond to the velocity head alone of the rotameter so as to bring the forces in the tube equilibrium. Knowing if there is no flow, then the float would remain at the bottom, so gas has to flow at a higher rate compared to the liquid so the float would be in a similar position making it easier to measure the flowrate. This leaves the gas rate to be determined too low.

5 0

2 years ago