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2 years ago

9

Select the correct scientific notation form of this numeral using only 2 significant figures. 5,489.6654

1 answer:

Levart [38]2 years ago

6 0

Answer:

5.4 × 10 3

Explanation:

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What is the part of plant from where <br>new flowers of fruit grows called

Andru [333]

Answer: it is called the ovary

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2 years ago

A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.01962 mol of

Scilla [17]

Answer:

The essence including its given problem is outlined in the following segment on the context..

Explanation:

The given values are:

Moles of CO₂,

x = 0.01962

Moles of water,

$\frac{y}{2} =0.01961$

$y=2\times 0.01961$

$=0.03922$

Compound's mass,

= 0.4647 g

Let the compound's formula will be:

$C_{x}H_{y}O_{z}$

Combustion's general equation will be:

⇒ $C_{x}H_{y}O_{z}+x+(\frac{y}{4}-\frac{z}{2}) O_{2}=xCO_{2}+\frac{y}{2H_{2}O}$

On putting the estimated values, we get

⇒ $12\times x=1\times y+16\times z=0.4647$

⇒ $12\times 0.01962+1\times 0.03922+16\times z=0.4647$

⇒ $0.27466+16z=0.4647$

⇒ $z=0.01187$

Now,

x : y : z = $0.01962:0.03922:0.01187$

= $\frac{0.01962}{0.0118}:\frac{0.03922}{0.0188}:\frac{0.0188}{0.0188}$

= $1.6:3.3:1.0$

= $3:6:2$

So that the empirical formula seems to be "C₃H₆O₂".

8 0

2 years ago

Be sure to answer all parts. In the average adult male, the residual volume (RV) of the lungs, the volume of air remaining after

Alenkinab [10]

<u>Answer:</u>

<u>For a:</u> The number of moles of air present in the RV is 0.047 moles

<u>For b:</u> The number of molecules of gas is $2.83\times 10^{22}$

<u>Explanation:</u>

<u>For a:</u>

To calculate the number of moles, we use the equation given by ideal gas follows:

$PV=nRT$

where,

P = pressure of the air = 1.00 atm

V = Volume of the air = 1200 mL = 1.2 L (Conversion factor: 1 L = 1000 mL)

T = Temperature of the air = $37^oC=[37+273]K=310K$

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

n = number of moles of air = ?

Putting values in above equation, we get:

$1.00atm\times 1.2L=n_{air}\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 310K\\n_{air}=\frac{1.00\times 1.2}{0.0821\times 310}=0.047mol$

Hence, the number of moles of air present in the RV is 0.047 moles

<u>For b:</u>

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.047 moles of air will contain $(0.047\times 6.022\times 10^{23})=2.83\times 10^{22}$ number of gas molecules.

Hence, the number of molecules of gas is $2.83\times 10^{22}$

7 0

2 years ago

It is known that the kinetics of recrystallization for some alloy obey the Avrami equation andthat the value of n in the exponen

Paul [167]

Answer:

rate of recrystallization = 4.99 × 10⁻³ min⁻¹

Explanation:

For Avrami equation:

$y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ k = \dfrac{-In(1-y)}{t^n}$

To calculate the value of k which is a dependent variable for the above equation ; we have:

$k = \dfrac{-In(1-0.40)}{200^{2.5}}$

$k = 9.030 \times 10 ^{-7}$

The time needed for 50% transformation can be determined as follows:

$y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ t =[ \dfrac{-In(1-y)}{k}]^{^{1/n}}$

$t_{0.5} =[ \dfrac{-In(1-0.4)}{9.030 \times 10^{-7}}]^{^{1/2.5}}$

= 200.00183 min

The rate of reaction for Avrami equation is:

$rate = \dfrac{1}{t_{0.5}}$

$rate = \dfrac{1}{200.00183}$

rate = 0.00499 / min

rate of recrystallization = 4.99 × 10⁻³ min⁻¹

8 0

3 years ago

What is the chemical reaction between an acid and a base which results in the formation of salt and water?

Tcecarenko [31]

Neutralization is the process in which anacid and base react to give salt and water

7 0

3 years ago