8 points

How many molecules of CaCi2 are equivalent to 75.9 grams

horsena [70]

<em>M CaCl₂: 40+(35,5×2) = 111 g/mol</em>

6,02·10²³ molecules ---------- 111g
X molecules --------------------- 75,9g
X = (75,9×<span>6,02·10²³)/111
X = <u>4,116</u></span><span><u>·10²³</u> molecules of CaCl</span>₂

:)

8 0

3 years ago

Basic substances have a gritty texture.

crimeas [40]

<h3>1.<u> Answer;</u></h3>

False

<h3><u>Explanation;</u></h3>

Bases have some of the following properties;

They have a bitter taste
They have a slimy, or soapy feel on fingers

Most bases react with acids and precipitate salts.
Strong bases may react violently with acids.

Bases turn red litmus paper blue

<h3>2. <u>Answer;</u></h3>

An acid

<h3><u>Explanation;</u></h3>

When acids are dissolved in water, the concentration of the acid decreases and it becomes dilute.
It dissociates in water to give H+ ions or hydrogen ions.
All acidic solutions contain more hydrogen ions than hydroxide ions, therefore when added to water it increases the concentration of H+ ions in water, as water is a neutral substance whose concentration of H+ ions is equal to OH-.

5 0

3 years ago

Whats 2736 +832091 +09281

astra-53 [7]

844108

One way is to write down all the numbers and add and write down each number.

5 0

3 years ago

How many moles of Cu(OH)2 are soluble in 1L of sodium hydroxide (NaOH) when the pH is 8.23?

Morgarella [4.7K]

Answer:

4.96E-8 moles of Cu(OH)2

Explanation:

Kps es the constant referring to how much a substance can be dissolved in water. Using Kps, it is possible to know the concentration of weak electrolytes. Then, pKps is the minus logarithm of Kps.

Now, we know that sodium hydroxide (NaOH) is a strong electrolyte, who is completely dissolved in water. Therefore the pH depends only on OH concentration originating from NaOH. Let us to figure out how much is that OH concentration.

$pH= -log[H]\\pH= -log (\frac{kw}{[OH]})$

$8.23 = - log(\frac{Kw}{[OH]} \\10^{-8.23} = Kw/[OH]\\ [OH] = Kw/10^{-8.23}$

$[OH]=1.69E-6$

This concentration of OH affects the disociation of Cu(OH)2. Let us see the dissociation reaction:

$Cu(OH)_2 -> Cu^{2+} + 2OH^-$

In the equilibrum, exist a concentration of OH already, that we knew, and it will be added that from dissociation, called "s":

The expression for Kps is:

$Kps= [Cu^{2+}] [OH]^2$

The moles of (CuOH)2 soluble are limitated for the concentration of OH present, according to the next equation.

$Kps= s*(2s+1.69E-6)^2$

"s" is the soluble quantity of Cu(OH)2.

The solution for this third grade equation is $s=4.96E-8 mol/L$

Now, let us calculate the moles in 1 L:

$moles Cu(OH)_2 = 4.96E-8 mol/L * 1 L = 4.96E-8 moles$

7 0

3 years ago

Balance these equations!<br> 1)<br> AIBr; +<br> K-<br> KBr +<br> AI

Tema [17]

Answer:

Instructions on balancing chemical equations:

Enter an equation of a chemical reaction and click 'Balance'. The answer will appear below

Always use the upper case for the first character in the element name and the lower case for the second character. Examples: Fe, Au, Co, Br, C, O, N, F. Compare: Co - cobalt and CO - carbon monoxide

To enter an electron into a chemical equation use {-} or e

To enter an ion specify charge after the compound in curly brackets: {+3} or {3+} or {3}.

Example: Fe{3+} + I{-} = Fe{2+} + I2

Substitute immutable groups in chemical compounds to avoid ambiguity.

For instance equation C6H5C2H5 + O2 = C6H5OH + CO2 + H2O will not be balanced,

but PhC2H5 + O2 = PhOH + CO2 + H2O will

Compound states [like (s) (aq) or (g)] are not required.

If you do not know what products are enter reagents only and click 'Balance'. In many cases a complete equation will be suggested.

Reaction stoichiometry could be computed for a balanced equation. Enter either the number of moles or weight for one of the compounds to compute the rest.

Limiting reagent can be computed for a balanced equation by entering the number of moles or weight for all reage

Explanation:

3 0

2 years ago