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Stells [14]
3 years ago
14

How are the elements arranged in the modern periodic table? mastering?

Chemistry
2 answers:
SIZIF [17.4K]3 years ago
6 0
Periodic table<span> of the </span>elements, in chemistry, the organized<span> array of all the chemical </span>elements<span> in order of increasing atomic number—i.e., the total number of protons in the atomic nucleus.</span>
ddd [48]3 years ago
5 0

Answer choices are:

A. by increasing atomic mass

B. by decreasing atomic mass

C. by increasing atomic number

D. by decreasing atomic number

____________________________________________________________

Correct answer choice is:

C. By increasing atomic number

____________________________________________________________

Explanation:

The modern periodic table is a table comprising the components organized in a progression of increasing atomic number. A vertical column termed as a group includes elements with related characteristics. A horizontal row is called a period.

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Which two compounds have the same molecular formula but different chemical and physical properties?
Artist 52 [7]
The answer is (4) CH3CH2OH and CH3OCH3. You need to figure out which pair has the same molecular formula which means that they have the same number of same atoms. Then you can get the write answer.
5 0
3 years ago
Read 2 more answers
Hydrazine (N2H4) is a fuel used by some spacecraft. It is normally oxidized by N2O4 according to the following equation: N2H4(l)
vitfil [10]

Answer:

The enthalpy of the reaction is coming out to be -380.16 kJ.

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as \Delta H

The equation used to calculate enthalpy change is of a reaction is:  

\Delta H_{rxn}=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]

For the given chemical reaction:

N_2H_4(l)+N_2O_4(g)\rightarrow 2N_2O(g)+2H_2O(g)

The equation for the enthalpy change of the above reaction is:

\Delta H_{rxn}=[(2 mol\times \Delta H_f_{(N_2O)})+(2 mol\times\Delta H_f_{(H_2O)} )]-[(1 mol\times \Delta H_f_{(N_2H_4)})+(1 mol\times \Delta H_f_{(N_2O_4)})]

We are given:

\Delta H_f_{(N_2O)}=81.6 kJ/mol\\\Delta H_f_{(H_2O)}=-241.8 kJ/mol\\\Delta H_f_{(N_2H_4)}= 50.6 kJ/mol\\\Delta H_f_{(N_2O_4)}=9.16 kJ/mo

Putting values in above equation, we get:

\Delta H_{rxn}=[(2 mol\times 81.6 kJ/mol)+2 mol\times -241.8 kJ/mol)]-[(1 mol\times (50.6 kJ/mol))+(1 mol\times (9.16))]\\\\\Delta H_{rxn}=-380.16 kJ

Hence, the enthalpy of the reaction is coming out to be -380.16 kJ.

6 0
3 years ago
The following is an example of what type of chemical reaction?
Svetlanka [38]
This is a D. combustion reaction

That is because you add O2 which is necessary for a combustion, while the results are CO2 and water. What you are missing is a ---> after the 2O2 (g)
4 0
3 years ago
Calcium carbonate is often used as an antacid. Your stomach acid is composed of HCl at a pH of 1.5. If you ate toooo much Turkey
stiks02 [169]

<u>Answer:</u> 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

<u>Explanation:</u>

pH is defined as the negative logarithm of hydrogen ion concentration present in the solution

pH=-\log [H^+]      .....(1)

Given value of pH = 1.5

Putting values in equation 1:

1.5=-\log[H^+]

[H^+]=10^{(-1.5)}=0.0316M

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

\text{Molarity of solution}=\frac{\text{Number of moles of solute}\times 1000}{\text{Volume of solution (mL)}}       .....(2)

We are given:

Volume of solution = 15.0 mL

Molarity of HCl = 0.0316 M

Putting values in equation 2:

0.0316=\frac{\text{Moles of HCl}\times 1000}{15.0}\\\\\text{Moles of HCl}=\frac{0.0316\times 15.0}{1000}=4.74\times 10^{-4}mol

The chemical equation for the reaction of HCl and calcium carbonate follows:

2HCl+CaCO_3\rightarrow H_2CO_3+CaCl_2

By the stoichiometry of the reaction:

2 moles of HCl reacts with 1 mole of calcium carbonate

So, 4.74\times 10^{-4}mol of HCl will react with = \frac{1}{2}\times 4.74\times 10^{-4}=2.37\times 10^{-4}mol of calcium carbonate

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

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

Moles of calcium carbonate = 2.37\times 10^{-4}mol

Molar mass of calcium carbonate = 100.01 g/mol

Putting values in the above equation:

\text{Mass of }CaCO_3=(2.37\times 10^{-4}mol)\times 100.01g/mol\\\\\text{Mass of }CaCO_3=0.0237g

Hence, 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

7 0
2 years ago
Which compound is an Arrhenius base?
Dmitry_Shevchenko [17]
I was hoping that some choices would be given to choose from. As there are no choices given, so i am answering the question based on my knowledge and hope that it comes to your help. Calcium hydroxide is a good example of Arrhenius base. An Arrhenius base is actually a substance that releases a hydroxyl ion in water.
3 0
3 years ago
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