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2 years ago

How many significant figures are there in the measurement 64,000 mg?

Chemistry

2 answers:

aivan3 [116]2 years ago

4 0

The answer is A because there is 2

DedPeter [7]2 years ago

3 0

For sig figs, you count the total number of numbers that aren’t 0, you only count 0 if they are after a decimal point. since there is not a decimal point, there are 2 significant figures, answer A

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What is the most striking part of the Rutherford scattering stimulation?

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Answer:

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2 years ago

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Answer:

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2 years ago

(5points) Na2[Fe(OH2)2(OH)I3]absorbs photons with energy of 191kJ/mol. Calculate the wavelength (in nm) for a photon absorbed by

AfilCa [17]

Answer:

626.7nm

Explanation:

The energy of a photon is defined as:

E = hc / λ

<em>Where E is the energy of the photon, h is Planck constant (6.626x10⁻³⁴Js), c is speed of light (3x10⁸m/s) and </em>λ is the wavelength of light

The energy of 1 photon is:

(191000 J / mol) ₓ (1 mole / 6.022x10²³) = 3.1717x10⁻¹⁹ J

Replacing:

3.1717x10⁻¹⁹ J = <em>6.626x10⁻³⁴Jsₓ3x10⁸m/s / </em>λ

λ = 6.267x10⁻⁷m

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2 years ago

For which of the following reactions is S° > 0. Choose all that apply. N2(g) + 3H2(g) 2NH3(g) 2C2H6(g) + 7O2(g) 4CO2(g) + 6H2

Lostsunrise [7]

Answer: $2C_2H_6(g)+7O_2(g)\rightarrow 4CO_2(g)+6H_2O(g)$

$NH_4I(s)\rightarrow NH_3(g)+HI(g)$

$2H_2O(g)+2SO_2(g)\rightarrow 2H_2S(g)+3O_2(g)$

Explanation:

Entropy is the measure of randomness or disorder of a system.

A system has positive value of entropy if the disorder increases and a system has negative value of entropy if the disorder decreases.

1. $N_2(g)+3H_2(g)\rightarrow 2NH_3(g)$

As 4 moles of gaseous reactants are changing to 2 moles of gaseous products, the randomness is decreasing and the entropy is negative

2. $2C_2H_6(g)+7O_2(g)\rightarrow 4CO_2(g)+6H_2O(g)$

As 9 moles of gaseous reactants are changing to 10 moles of gaseous products, the randomness is increasing and the entropy is positive.

3. $NH_4I(s)\rightarrow NH_3(g)+HI(g)$

As 1 mole of solid reactants is changing to 2 moles of gaseous products, the randomness is increasing and the entropy is positive.

4. $2H_2O(g)+2SO_2(g)\rightarrow 2H_2S(g)+3O_2(g)$

As 4 moles of gaseous reactants is changing to 5 moles of gaseous products, the randomness is increasing and the entropy is positive

5. $2NO(g)+2H_2(g)\rightarrow N_2(g)+2H_2O(l)$

As 4 moles of gaseous reactants is changing to 1 moles of gaseous products, the randomness is decreasing and the entropy is negative.

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2 years ago