All samples of a specific substanice have the same chemical<br> composition<br> TRUE<br> FALSE

What is the [H+] and [OH-] of a 3.5 M HCIO3 solution?

levacccp [35]

Answer: H+ ia helyuim

explinanation: Hope this helped!!

3 0

3 years ago

How many grams are in 0.35 moles of C2H4? please show dimensional analysis

fredd [130]

Answer:

9.8g

Explanation:

Using periodic table find molar mass of C and H:

C=12.01g/mol

H=1.008g/mol

Molar mass of C2H4=(12.01)2+(1.008)4=28.03g/mol

Using molar mass times moles of the chemical to find the mass in 0.35 moles of c2h4:

28.03 x 0.35=9.8grams

5 0

3 years ago

The rate constant k for a certain reaction is measured at two different temperatures:

bogdanovich [222]

Answer:

Ea=5.5 Kcal/mole

Explanation:

Let rate constant are $K_1$ and $K_2$ at temperature $T_1$ and $T_2$

By using Arrhenius equation at two different two different temperature,

$Log K_1/K_2 =E_a/2.303R*(1/T_2 -1/T_2 );T_1=273+376=649K ;K_1=4.8*10^8;T_2=273+280=553K ;K_2=2.3*10^8;R=2 cal/(mole.K);Log (4.8*10^8)/(2.3*10^8 )=E_a/2.303R*(1/553K-1/649); Log 4.8/2.3=E_a/2.303R*96/358897 ;0.32=E_a/2.303R*96/358897;E_a=(0.32*2.303R*358897)/96;$

By putting value of R=2 cal/mole.K

$E_a=5510.265cal/mole;$

By rounding off upto 2 significant figure;

$E_a=5.5Kcal/mole;$

8 0

4 years ago

A sample of H2 gas (12.28 g) occupies 100.0 L at 400.0 K and 2.00 atm. A sample weighing 9.49 g occupies ________ L at 353 K and

lutik1710 [3]

Considering the ideal gas law, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.

Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P× V = n× R× T

In this case, you know:

P= 2 atm
V= ?
n= $9.49 gramsx\frac{1 mole}{2 grams} = 4.745moles$ being 2g/mole the molar mass of H2, that is, the amount of mass that a substance contains in one mole.
R= 0.082 $\frac{atmL}{molK}$
T= 353 K

Replacing:

2 atm× V = 4.745 moles× 0.082 $\frac{atmL}{molK}$ × 353 K

Solving:

V = (4.745 moles× 0.082 $\frac{atmL}{molK}$ × 353 K)÷ 2 atm

Finally, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.

Learn more:

brainly.com/question/4147359?referrer=searchResults

5 0

3 years ago

Which statement BEST describes the policies of the Freedmen's Bureau? Question 1 options: The Freedmen's Bureau wanted to encour

bekas [8.4K]

<h2>ANSWER:</h2>

The Freedman's Bureau wanted to help newly freed slaves participate in American society.

<h2>EXPLANATION:</h2>

The Freedmen's Bureau, formally known as the Bureau of Refugees, Freedmen and Abandoned Lands, was set up in 1865 by Congress to help a large number of previous dark slaves and poor whites in the South in the outcome of the Civil War. The Freedmen's Bureau given nourishment, lodging, and therapeutic guide built up schools and offered lawful help. It additionally endeavored to settle previous slaves ashore appropriated or surrendered amid the war. Be that as it may, the department was kept from completely doing its projects because of a lack of assets and faculty, alongside the legislative issues of race and Reconstruction.

6 0

3 years ago

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All samples of a specific substanice have the same chemical composition TRUE FALSE