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2 years ago

Help please all please

Chemistry

2 answers:

Luden [163]2 years ago

5 0

Answer:

I don’t want to download a pdf that I don’t know what it is…

Also, brainly strictly says that we can’t post questions about a test or quiz that is found in school…

Explanation:

Lilit [14]2 years ago

3 0

Answer:

wnich subject and which class pdf i will help you tell me

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Which part of the periodic table contains elements with the greatest metallic properties?

KiRa [710]

The bottom of group 1. Francium (or Fr) is the element with the greatest metallic properties.

Francium is not a naturally-occurring element, however. It is man-made. There is an isotope of francium that exists naturally, but it's half life is so short that it decays almost instantly into a different element.

The naturally-occurring element with the highest metallic properties is cesium (or Cs), located right above francium.

Metallic characteristics decrease as you move from left to right on the periodic table.

7 0

2 years ago

The equilibrium constant for the reaction AgBr(s) Picture Ag+(aq) + Br− (aq) is the solubility product constant, Ksp = 7.7 × 10−

barxatty [35]

Answer:

The reaction will be non spontaneous at these concentrations.

Explanation:

$AgBr(s)\rightarrow Ag^+(aq) + Br^- (aq)$

Expression for an equilibrium constant $K_c$ :

$K_c=\frac{[Ag^+][Br^-]}{[AgCl]}=\frac{[Ag^+][Br^-]}{1}=[Ag^+][Br^-]$

Solubility product of the reaction:

$K_{sp}=[Ag^+][Br^-]=K_c=7.7\times 10^{-13}$

Reaction between Gibb's free energy and equilibrium constant if given as:

$\Delta G^o=-2.303\times R\times T\times \log K_c$

$\Delta G^o=-2.303\times R\times T\times \log K_{sp}$

$\Delta G^o=-2.303\times 8.314 J/K mol\times 298 K\times \log[7.7\times 10^{-13}]$

$\Delta G^o=69,117.84 J/mol=69.117 kJ/mol$

Gibb's free energy when concentration $[Ag^+] = 1.0\times 10^{-2} M$ and $[Br^-] = 1.0\times 10^{-3} M$

Reaction quotient of an equilibrium = Q

$Q=[Ag^+][Br^-]=1.0\times 10^{-2} M\times 1.0\times 10^{-3} M=1.0\times 10^{-5}$

$\Delta G=\Delta G^o+(2.303\times R\times T\times \log Q)$

$\Delta G=69.117 kJ/mol+(2.303\times 8.314 Joule/mol K\times 298 K\times \log[1.0\times 10^{-5}])$

$\Delta G=40.588 kJ/mol$

For reaction to spontaneous reaction: $\Delta G$ .
For reaction to non spontaneous reaction: $\Delta G>0$ .

Since ,the value of Gibbs free energy is greater than zero which means reaction will be non spontaneous at these concentrations

5 0

2 years ago

A 35.0 ml sample of 0.225 m hbr was titrated with 42.3 ml of koh. What is the concentration of the koh?

Lemur [1.5K]

Answer:

The concentration of KOH is 0.186 M

Explanation:

First things first, we need too write out the balanced equation between HBr and KOH.

This is given as;

KOH (aq) + HBr (aq) → KBr (aq) + H2O (l)

From the reaction above, we can tell that it takes 1 mole of KOH to react with 1 mole of HBr.

We use the acid base formular in calculating unknown concentrations. This is given as;

$\frac{CaVa}{CbVb} = \frac{na}{nb}$

where;

Ca = Concentration of acid

Va = Volume of acid

Cb = Concentration of base

Vb = Volume of base

na = Number of moles of acid

nb = Number of moles of base

KOH is the base and HBr is acid.

Hence;

Ca = 0.225

Va = 35

Cb = ?

Vb = 42.3

na = 1

nb = 1

Making Cb subject of formular we have;

$Cb = \frac{CaVaNb}{VbNa}$

Cb = (0.225 * 35 * 1) / (42.3 * 1)

Cb = 0.186 M

5 0

2 years ago

The law of universal gravitation describes the gravitational force between two objects.

Sliva [168]

Answer:

mass and distance

Explanation:

The strength of this force depends on the <u>mass</u>

of each object and

the <u>distance</u>

between them.

6 0

1 year ago

All isotopes of a particular element have the same atomic number. how then do the isotopes of a particular element differ?

White raven [17]

They have less or more neutrons. Isotopes have same number of protons but different number of neutrons.

4 0

3 years ago

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