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3 years ago

What is the number of molecule(s)?

Chemistry

2 answers:

Gemiola [76]3 years ago

5 0

1. 4NHCO3

2. 3CaCO3

3. 5NaC2H3O

4. 6NH3

5. 2CaCl2O2

ans ( a). NHCO3

Svet_ta [14]3 years ago

3 0

I think it’s 2 not sure I don’t remember this stuff

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Cu + 2AgNO3 →

netineya [11]

Answer: 292.54g of Ag

Explanation:

Cu + 2AgNO3 →Cu(NO3)2 + 2 Ag

mass conc. Of Ag = n x molar Mass

Mass conc. Of Ag = 2 x 108 = 216g

From the equation,

63.5g of Cu produced 216g of Ag

Therefore, 86g of Cu will produce Xg of Ag. i.e

Xg of Ag = (86 x 216)/63.5 = 292.54g

5 0

3 years ago

The tendency of an element to react is closely related to

Bad White [126]

C. The number of Valence electrons,
Every atom tries to follow the Octet rule i.e To have 8 electrons in its Valence shell.
Every atom tries to accomodate 8 electrons in its Valence shell to stabilize themselves, Metals usually have 1-3 eletrons in their Valence shell which they donate to non metals so their Valnce shell has 8 electroons, (The previous will now be the Valence shell and it will be full)
Similarly Non metals have 4-7 electrons, they accept electrons from metals so they can have 8 electrons in their Valence shell.
Noble gases already have 8 electrons in their Valance shell, so they do not react and stable.

Hope it helps :)

8 0

3 years ago

Name three elements that are named after people.

natali 33 [55]

Answer:

Bohrium (Niels Bohr)

Curium (Marie and Pierre Curie)

Einsteinium (Albert Einstein

4 0

2 years ago

Read 2 more answers

The average C - H bond energy in CH4 is 415 kJ / mol. Use the following data to calculate the average C - H bond energy in ethan

sertanlavr [38]

Answer and Explanation:

ΔH = (Bond energies of the products) - (Bond Energies of the reactants)

a) C2H6 + H2 ----> 2CH4 ΔH = -65.07 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H6 + Bond energy of H2

Bond energy of C2H6 = (C-C) + 6(C-H) = 347 + 6(C-H)

Bond energy of H2 = (H-H) = 432 KJ/mol

-65.07 = 3320 - (Bond energy of C2H6 + 432)

Bond energy of C2H6 = 3320-432+65.07 = 2953.07 KJ/mol

Bond energy of C2H6 = (C-C) + 6(C-H) = 347 + 6(C-H) = 2953.07

(C-H) = (2953.07 -347)/6 = 434.345 KJ/mol

b) C2H4 + 2H2 ------> CH4 ΔH = -202.21 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H4 + (2 × Bond energy of H2)

Bond energy of C2H4 = (C=C) + 4(C-H) = 614 + 4(C-H)

(2 × Bond energy of H2) = 2 × 432 = 864 KJ/mol

-202.21 = 3320 - (Bond energy of C2H4 + 864)

Bond energy of C2H4 = 3320+202.21-864 = 2658.1 KJ/mol

Bond energy of C2H4 = (C=C) + 4(C-H) = 614 + 4(C-H) = 2658.1

(C-H) = (2658.1 - 614)/4 = 511.05 KJ/mol

c) C2H2 + 3H2 ------> 2CH4 ΔH = -376.74 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H2 + (3 × Bond energy of H2)

Bond energy of C2H = (triple bond Carbon to Carbon) + 2(C-H) = 839 + 2(C-H)

(3 × Bond energy of H2) = 3 × 432 = 1296 KJ/mol

-376.74 = 3320 - (Bond energy of C2H2 + 1296)

Bond energy of C2H2 = 3320+376.74-1296 = 2400.74 KJ/mol

Bond energy of C2H2 = (triple bond Carbon to Carbon) + 2(C-H) = 839 + 2(C-H) = 2400.74

(C-H) = (2400.74 - 839)/2 = 780.87 KJ/mol

QED!!!

6 0

4 years ago

How waves affect matter at the macroscopic and particle levels?

solmaris [256]

Reflection, refraction, and diffraction

Reflection occurs when waves bounce back from a surface that they cannot pass through. Refraction occurs when waves bend as they enter a new medium at an angle and start traveling at a different speed.

5 0

3 years ago