All categories

4 years ago

The acidity or alkalinity (basicity ) of an unknown aqueous solution is indicated by its

1 answer:

7 0

The correct answer is A. PH value

If a substance is very acidity it has a high PH, if it is less acidic (alkalinity) is has a lower PH. For instance, water has a PH of 7 because it is in between of being acidic and alkaline.

You might be interested in

How many moles of oxygen are in 1 mole of iron (II) nitrate?

Alekssandra [29.7K]

Answer:

Explanation:

One mole of Fe(NO3)3, or iron(III) nitrate, has three moles of nitrate molecules, which have three moles of oxygen atoms each. We can show this mathematically:

1 mole Fe(NO3)3 * (3 moles NO3)/(1 mole Fe(NO3)3) = 3 moles NO3

3 moles NO3 * (3 moles Oxygen)/(1 mole NO3) = 9 moles Oxygen

9 moles of Oxygen in one mole Fe(NO3)3

3 0

3 years ago

Read 2 more answers

1. Sodium and water react according to the following equation. If 31.5g of sodium are added to excess water, how many liters of

Vika [28.1K]

<h3> Question 1</h3>

The number of liter of hydrogen gas that are formed at STP is

15.344 L

<u><em> calculation</em></u>

calculate the moles of Na

moles =mass/molar mass

from periodic table the molar mass of Na = 23 g/mol

moles = 31.5 g /23 g /mol = 1.37 moles

From equation above the mole ratio of Na: H2 is 2:1

therefore the moles of H2 =1.37 x1/2 =0.685 moles

At STP 1 moles of a gas = 22.4 L

0.685 moles = ? L

by cross multiplication

=[ (0.685 moles x 22.4 L) / 1 mole =15.344 L

<h3> Question 2</h3>

The percent yield = 84.77%

<u><em>calculation</em></u>

4 Na + O₂ → 2 Na₂O

%yield =actual yield / theoretical yield x 100

Actual yield= 61.8 g

<em>The theoretical yield is calculated as below</em>

Step 1: find the moles of Na

moles = mass /molar mass

from periodic table the molar mass of Na = 23 g/mol

moles = 54.1 g /23 g/mol =2.352 moles

Step 2: use the mole ratio to determine the moles of Na₂O

Na:Na₂O is 4: 2 therefore the moles of Na₂O = 2.352 x 2/4 =1.176 moles

Step 3: find the theoretical mass of Na₂O

mass = moles x molar mass

The molar mass of Na₂O = [(23 x 2 ) + 16] =62 g/mol

mass = 1.176 moles x 62 g/mol = 72.9 g

% yield is therefore = 61.8 g /72.9 x 100 = 84.77%

8 0

3 years ago

When the following equation is balanced using the smallest possible integers, what is the number in front of the substance in bo

weeeeeb [17]

The balanced equation :

8Al + 3Fe₃O₄→ 4Al₂O₃ + 9Fe

You just have to look for which element is in bold because the question is not clear

<h3>Further explanation</h3>

Equalization of chemical reaction equations can be done using variables. Steps in equalizing the reaction equation:

1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c etc.

2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index between reactant and product

3. Select the coefficient of the substance with the most complex chemical formula equal to 1

Reaction

Al + Fe₃O₄→ Al₂O₃ + Fe

give a coefficient

aAl + Fe₃O₄→ bAl₂O₃ + cFe

O, left=4, right=3b⇒3b=4⇒b=4/3

Al, left=a, right=2b⇒a=2b⇒a=2.4/3⇒a=8/3

Fe, left=3, right=c⇒c=3

The equation becomes :

8/3Al + Fe₃O₄→ 4/3Al₂O₃ + 3Fe x3

8Al + 3Fe₃O₄→ 4Al₂O₃ + 9Fe

7 0

3 years ago

Calculate the vapor pressure (in torr) at 298 K in a solution prepared by dissolving 46.8 g of the non-volatile non-electrolye g

Rainbow [258]

<u>Answer:</u> The total partial pressure of the solution is 131.37 torr.

<u>Explanation:</u>

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

<u>For glucose:</u>

Given mass of glucose = 46.8 g

Molar mass of glucose = 180 g/mol

Plugging values in equation 1:

$\text{Moles of glucose}=\frac{46.8g}{180g/mol}=0.26 mol$

<u>For methanol:</u>

Given mass of methanol = 117 g

Molar mass of methanol = 32 g/mol

Plugging values in equation 1:

$\text{Moles of methanol}=\frac{117g}{32g/mol}=3.66 mol$

Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:

$\chi_A=\frac{n_A}{n_A+n_B}$ .....(2)

where n is the number of moles

Putting values in equation 2:

$\chi_{methanol}=\frac{3.66}{0.26+3.66}=0.934$

Raoult's law is the law used to calculate the partial pressure of the individual gases present in the mixture. The equation for Raoult's law follows:

$p_A=\chi_A\times p_T$ .....(3)