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blagie [28]
3 years ago
8

Help brainliest plzzzz

Chemistry
2 answers:
Anit [1.1K]3 years ago
7 0
The answer is 4 I think
konstantin123 [22]3 years ago
6 0
The awnser is D or the 4th one
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Which of the following is a homogeneous mixture of two or more pure substances? Water alcohol coffee mercury
Murrr4er [49]

i think coffee

is the answer

8 0
3 years ago
When 1.104 grams of iron metal are mixed with 26.023 grams of hydrochloric acid in a coffee cup calorimeter, the temperature ris
Alika [10]

Answer:

a) An exothermic reaction, will release heat. No heat will be absorbed.

b) 903.71 J  of heat released

c) reaction is exothermic and ∆H will be negative.

d) ΔHreaction = 818.6 J/g

e)  ΔHreaction = 45.6 kJ/mol

f) ΔHreaction = 91.2 kJ

Explanation:

<u>Step 1:</u> Data given

Mass of iron = 1.104 grams

Mass of hydrochloric acid = 26.023 grams

Initial temperature = 25.2°C

Final temperature = 33.5 °C

Temperature change = 8.3 °C

<u>Step 2:</u> The balanced equation

2Fe(s)+6HCl(aq) → 2FeCl3 (aq)+3H2 (g)

(A)  Determine the amount of heat (in J) absorbed by the reaction mixture.

Since we have a rise of temperature, this means the reaction is exothermic.

An exothermic reaction, will release heat. No heat will be absorbed.

(B)  How much heat (in J) was released by the reaction that occurred?

q = mC∆T

with q = heat released (in J)

with m = the mass (in grams)

with c = the specific heat capacity (in J/g°C)

with  ∆T  = The change in temperature (in °C)

q = (26.023g)*(4.184 J/g°C)*(8.3 °C) = 903.71 J  of heat released

(C)  Is this reaction exothermic or endothermic? Is ΔHreaction positive or negative?

Since we have a rise of temperature, this means the reaction is exothermic.

There is heat released so ∆H will be negative.

(D)  Under constant pressure conditions (as used in this experiment), the heat released by the reaction equals the reaction enthalpy, qreleased = ΔHreaction. Determine ΔHreaction in Joules per gram of metal used (J/g).

ΔHreaction = 903.71 J/1.104 g = 818.6 J/g

(E) Determine ΔHreaction in kilojoules per mole of metal used (kJ/mol)

Number of moles of iron =1.104 grams / 55.845 g/mol = 0.0198 moles

ΔHreaction = 903.71 J / 0.0198 moles = 45641.9 J/mol = 45.6 kJ/mol

(F)  Determine ΔHreaction in kilojoules per mole for the balanced reaction equation provided

Since we have 2moles of Fe in the balanced reaction;

ΔHreaction = 45.6 kJ/mol * 2 mol = 91.2 kJ

7 0
2 years ago
What is the name of the compound with the formula NH HCO3 ?
svet-max [94.6K]

Answer:

Acid ammonium carbonate // Ammonium bicarbonate.

Explanation:

Hello, a 4 is missing in the fist H, thus:

NH_4HCO_3

The presence of the hydrogen between the ammonium and the carbonates characterizes the salt as an acid salt, so you could name it as acid ammonium carbonate or ammonium bicarbonate (similar to the sodium bicarbonate which is NaHCO_3).

Best regards.

6 0
2 years ago
Who established atomic numbers as the basis for organizing the periodic table?
Jobisdone [24]

Answer:

Henry Moseley.

Explanation:

Hello,

Henry Moseley's work stated that it is better to organize the periodic table in the light of the atomic number (which accounts for the amount of protons and electrons) instead of the atomic mass, because atomic numbers are not arbitrarily assigned as long as they have the aforesaid physical basis.

Best regards.

3 0
2 years ago
What is the mass number of an iron atom that has 29 neutrons?
hjlf

Answer:

The answer is 54

Explanation:

8 0
2 years ago
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