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3 years ago

Iron is denser than helium. True or false

Chemistry

1 answer:

Delicious77 [7]3 years ago

4 0

Explanation:

Elements heavier than Helium are synthesized in a number of environments. For elements that are lighter than Iron, those elements are synthesized during various phases in the evolution of massive stars. For elements heavier than Iron, one needs quite a bit of energy input to form these heavy elements.

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3.364 g of hydrated barium chloride of BaCL2.xH2O was dissolved in water and made up to a total volume of 250.0 mL. 10.00 mL of

atroni [7]

Given:

Mass of hydrated barium chloride = 3.364 g

Total volume of barium chloride V(total)= 250 ml

Volume taken for titration V = 10 ml

Volume of AgNO3 consumed = 46.92 ml

Concentration of AgNO3 = 0.0253 M

To determine:

The value of x i.e. the water of hydration in BaCl2

Explanation:

The net ionic equation is-

Ag⁺(aq) + Cl⁻(aq) → AgCl(s)

Based on the reaction stoichiometry: Equal moles of Ag+ and Cl- combine to form AgCl

Moles of Ag+ consumed = moles of Cl- present

Moles of Ag+ = V(AgNO3) * M(AgNO3) = 0.04692 * 0.0253 = 0.00119moles

Moles of Cl- present = 0.00119 moles

Thus, 0.00119 moles of Cl- are present in 10 ml of the solution

Therefore, number of moles of Cl- in 250 ml would be-

= 0.00119 * 250 /10 = 0.02975 moles of cl-

Now:

2 moles of Cl- are present in 1 mole of BaCl2

Therefore, 0.02975 moles of Cl- correspond to- 0.02975 * 1/2 = 0.01488 moles of BaCl2

Molar mass of BaCl2 = 208.22 g/mol

Thus, mass of BaCl2 = 0.01488 moles * 208.22 g.mol-1 = 3.098 g

Mass of water of hydration = 3.364 - 3.098 = 0.266 g

# moles of water 'x' = .266/18 = 0.015 ≅ 1

Ans: Formula for hydrated barium chloride = BaCl2. 1H2O

7 0

4 years ago

11. Assuming that the gases are ideal, calculate the amount of work done (joules) in each of the following reactions at 25 degre

gayaneshka [121]

Answer:

For a: Work done for the given reaction is 2477.572 J.

For b: Work done for the given reaction is 0 J

Explanation:

To calculate the work done for the reaction, we use the equation:

$W=-P\Delta V$

Ideal gas equation follows:

$PV=nRT$

Relating both the above equations, we get:

$W=-\Delta n_gRT$ ......(1)

where,

$\Delta n_g$ = difference in number of moles of products and reactants = $n_g_{(products)}-n_g_{(reactants)}$

R = Gas constant = 8.314 J/K.mol

T = temperature = $25^oC=[273+25]K=298K$

For a:

The chemical reaction follows:

$4HCl(g)+O_2(g)\rightarrow 2Cl_2(g)+2H_2O(g)$

$\Delta n_g=4-5=-1$

Putting values in equation 1, we get:

$W=-(-1mol)\times (8.314J/K.mol)\times 298K=2477.572J$

Hence, work done for the given reaction is 2477.572 J.

For b:

The chemical reaction follows:

$2NO(g)\rightarrow N_2(g)+O_2(g)$

$\Delta n_g=2-2=0$

Putting values in equation 1, we get:

$W=-(0mol)\times (8.314J/K.mol)\times 298K=0J$

Hence, work done for the given reaction is 0 J.

3 0

3 years ago

Richard made the following table that highlights all the different constellations, or patterns of stars, he observed in each sea

Scilla [17]

I’m a leo purrr and I’m pretty sure it’s number 4

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3 years ago

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Calculate the ΔG for the following system. Then state if the system is spontaneous or not spontaneous.

skad [1K]

+25 kJ; not spontaneous is your answer :) Hope this helps.

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3 years ago

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net ionic equation to show the reaction of aqueous lead(II) nitrate with aqueous potassium sulfate to form solid lead(II) sulfat

Masja [62]

Net ionic equation: Pb²⁺ + SO₄²⁻ → PbSO₄

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4 years ago

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