All categories

3 years ago

Glve the number of significant figures in this number: 40

Chemistry

2 answers:

trapecia [35]3 years ago

4 0

Answer:

the number of significant figures in this number is two because non-zero digits are always significant and a final zero or trailing zero is always counted

Explanation:

i hope this will help you :)

Eddi Din [679]3 years ago

3 0

Answer:

only 4 is the significant figure

we take tailing zeroes as significant figures only in case of decimals

You might be interested in

1. What is the equality between mL and L?

Mice21 [21]

Answer:

1 liter (L) = 1000 milliliters (mL)

Explanation:

5 0

3 years ago

How many moles are present in 25.0 grams of potassium permanganate, KMnO,?

poizon [28]

Answer: 0.158

Explanation:

7 0

3 years ago

A mouse is placed in a sealed chamber with air at 769.0 torr. This chamber is equipped with enough solid KOH to absorb any CO2 a

svlad2 [7]

Answer: The amount of oxygen gas consumed by mouse is 0.202 grams.

Explanation:

We are given:

Initial pressure of air = 769.0 torr

Final pressure of air = 717.1 torr

Pressure of oxygen = Pressure decreased = Initial pressure - Final pressure = (769.0 - 717.1) torr = 51.9 torr

To calculate the amount of oxygen gas consumed, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 51.9 torr

V = Volume of the gas = 2.20 L

T = Temperature of the gas = 292 K

R = Gas constant = $62.364\text{ L. Torr }mol^{-1}K^{-1}$

n = number of moles of oxygen gas = ?

Putting values in above equation, we get:

$51.9torr\times 2.20L=n\times 62.364\text{ L. Torr }mol^{-1}K^{-1}\times 292K\\\\n=\frac{51.9\times 2.20}{62.364\times 292}=0.0063mol$

To calculate the mass from given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of oxygen gas = 0.0063 moles

Molar mass of oxygen gas = 32 g/mol

Putting values in above equation, we get:

$0.0063mol=\frac{\text{Mass of oxygen gas}}{32g/mol}\\\\\text{Mass of oxygen gas}=(0.0063mol\times 32g/mol)=0.202g$

Hence, the amount of oxygen gas consumed by mouse is 0.202 grams.

5 0

3 years ago

trial 2, 2.68 g/cm/3 trial 3, 2.84g/cm/3. aluminum has a density of 2.70g/cm/3 calcute the percent error for each trial.

serg [7]

Answer:

trial 2: 0.74

trial 3: 5.19

I think but the equation for sloving percent error is:

(true value - determined value)/true value * 100

Explanation:

6 0

3 years ago

Is a oreo a pure substance or a mixture

adoni [48]

Belive it or not but an oreo is a mixture. LOL

7 0

3 years ago