All categories

3 years ago

Write 450.0000345 in Scientific Notation with 4 significant figures.

Chemistry

1 answer:

alina1380 [7]3 years ago

4 0

Answer:

$4.500\times 10^{2}$

Explanation:

Scientific notation is the way of writing numbers which are either large or small. The number is written in the scientific notation when the number is between 1 and 10 and then multiplied by the power of 10.

The given number:

450.0000345 can be written as $4.500000345\times 10^{2}$

Answer upto 4 significant digits = $4.500\times 10^{2}$

You might be interested in

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L. For the water to be safe for drinking, the c

Shalnov [3]

Answer:

Approximately 22.37 days, will it take for the water to be safe to drink.

Explanation:

Using integrated rate law for first order kinetics as:

$[A_t]=[A_0]e^{-kt}$

Where,

$[A_t]$ is the concentration at time t

$[A_0]$ is the initial concentration

k is rate constant

Given that:- k = 0.27 (day)⁻¹

$[A_0]$ = 0.63 mg/L

$[A_t]=1.5\times 10^{-3}$ mg/L

Applying in the above equation as:-

$1.5\times 10^{-3}=0.63e^{-0.27\times t}$

$63e^{-0.27t}=150\times \:10^{-3}$

$e^{-0.27t}=\frac{1}{420}$

$t=\frac{100\ln \left(420\right)}{27}=22.37$

<u>Approximately 22.37 days, will it take for the water to be safe to drink.</u>

7 0

4 years ago

What happens to concrete when it's no longer needed

Sveta_85 [38]

Did you mean when it is a liquid?

8 0

3 years ago

2. Why does the CDC recommend hand sanitizers with at least 60% alcohol?! I

choli [55]

Answer:

Here's it:

Explanation:

Germs are everywhere! They can get onto hands and items we touch during daily activities and make us sick. Cleaning hands at key times with soap and water or hand sanitizer that contains at least 60% alcohol is one of the most important steps you can take to avoid getting sick and spreading germs to those around you.

There are important differences between washing hands with soap and water and using hand sanitizer. Soap and water work to remove all types of germs from hands, while sanitizer acts by killing certain germs on the skin. Although alcohol-based hand sanitizers can quickly reduce the number of germs in many situations, they should be used in the right situations.

3 0

3 years ago

Which of the following statements concerning the density of a gas is true?

Naya [18.7K]

Answer:

can u give us the options

5 0

3 years ago

Four gases were combined in a gas cylinder with these partial pressures: 3.5 atm N2, 2.8 atm O2, 0.25 atm Ar, and 0.15 atm He.

Cerrena [4.2K]

Answer:

Answer :

The total pressure inside the cylinder is, 6.7 atm

The mole fraction of N_2 in the mixture is, 0.52

Solution :

First we have to calculate the total pressure inside the cylinder.

According to the Dalton's law, the total pressure of the gas is equal to the sum of the partial pressure of the mixture of gasses.

P_T=p_{N_2}+p_{O_2}+p_{Ar}+p_{He}

Now put all the given values is expression, we get the total pressure inside the cylinder.

P_T=3.5+2.8+0.25+0.15=6.7atm

Now we have to calculate the mole fraction of N_2 in the mixture.

Formula used :

pN_2=XN_2 x P_T

where,

P_T = total pressure = 6.7 atm

pN_2 = partial pressure of nitrogen gas = 3.5 atm

XN_2 = mole fraction of nitrogen gas = ?

Now put all the given values in the above formula, we get

3.5atm=XN_2 x 6.7atm

XN_2=0.52

Therefore, the total pressure inside the cylinder is, 6.7 atm and the mole fraction of N_2 in the mixture is, 0.52

Hope it helps answer the question:)

5 0

3 years ago