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3 years ago

6

Geologists apply various methods to study the layers of the earth. Which if the following is a method used to study the deaths l

ayers

1 answer:

timama [110]3 years ago

6 0

Answer: ???

Explanation:???

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Which is a property of barium (Ba)?

777dan777 [17]

Answer:

i think but i am not sure but according to me it mainly reacts yo non metals and i think its very reactive if my answer is wrong then comment below this question i will see it and i will get an opportunity to learn something new

4 0

3 years ago

If an equal number of moles of reactants are used, do the following equilibrium mixtures contain primarily reactants or products

puteri [66]

<u>Answer:</u>

<u>For a:</u> The equilibrium mixture contains primarily reactants.

<u>For b:</u> The equilibrium mixture contains primarily products.

<u>Explanation:</u>

There are 3 conditions:

When $K_{eq}>1$ ; the reaction is product favored.
When $K_{eq}$ ; the reaction is reactant favored.
When $K_{e}=1$ ; the reaction is in equilibrium.

For the given chemical reactions:

<u>For a:</u>

The chemical equation follows:

$HCN(aq.)+H_2O(l)\rightleftharpoons CN^-(aq.)+H_3O^+(aq.);K_{eq}=6.2\times 10^{-10}$

The expression of $K_{eq}$ for above reaction follows:

$K_{eq}=\frac{[CN^-][H_3O^+]}{[HCN][H_2O]}=6.2\times 10^{-10}$

As, $K_{eq}$ , the reaction will be favored on the reactant side.

Hence, the equilibrium mixture contains primarily reactants.

<u>For b:</u>

The chemical equation follows:

$H_2(g)+Cl_2(g)\rightleftharpoons 2HCl(g);K_{eq}=2.51\times 10^{4}$

The expression of $K_{eq}$ for above reaction follows:

$K_{eq}=\frac{[HCl]^2}{[H_2][Cl_2]}=2.51\times 10^{4}$

As, $K_{eq}>1$ , the reaction will be favored on the product side.

Hence, the equilibrium mixture contains primarily products.

4 0

3 years ago

A 0.5895-g sample of impure magnesium hydroxide is dissolved in 100.0 mL of 0.2050 M HCl solution. The excess acid then needs 19

Zepler [3.9K]

Answer:

91.38 %

Explanation:

First we use the following formula to calculate the number of moles of HCl and NaOH contained in the solutions:

molar concentration = number of moles / solution volume

number of moles = molar concentration × solution volume

number of moles of HCl = 0.2050 × 100 = 20.5 mmoles

number of moles of NaOH = 0.1020 × 19.85 = 2.02 mmoles

reaction between NaOH and HCl:

NaOH + HCl → NaCl + H₂O

If 2.02 mmoles of NaOH were used for neutralization of HCl left from the reaction, which are 2.02 mmoles of HCl, it means that the HCl reacted with Mg(OH)₂:

20.5 - 2.02 = 18.48 mmoles of HCl

2 HCl + Mg(OH)₂ = MgCl₂ + 2 H₂O

From the chemical reaction we devise the following reasoning:

if 2 mmoles of HCl react with 1 mmole of Mg(OH)₂

then 18.48 mmoles HCl react with X mmoles of Mg(OH)₂

X = (18.48 × 1) / 2 = 9.24 mmoles of Mg(OH)₂

now the mass of Mg(OH)₂:

mass = number of moles × molecular weight

mass of Mg(OH)₂ = 9.24 × 58.3 = 538.7 mg = 0.5387 g

Now the percent by mass of magnesium hydroxide Mg(OH)₂ in the impure sample (purity):

purity = (mass of pure Mg(OH)₂ / mass of impure sample) × 100

purity = (0.5387 / 0.5895) × 100

purity = 91.38 %

7 0

3 years ago

Arrange these elements according to increasing reactivity: Br, I, F, Cl

zzz [600]

It should be I, Br, Cl, F

7 0

3 years ago

Which of these following have a positive charges

Over [174]

Talking about ions, a cation has a positive charge. That means a positive charge is gained by an atom that gives out electrons.

7 0

3 years ago