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2 years ago

Please someone help or tell me the answer for number 2 its a quiz grade

Chemistry

1 answer:

zubka84 [21]2 years ago

5 0

Answer:

1 rearrange the equation

Explanation:

3c + 2h 2 = 2 c3h4

3c +2h2 = c3 h4

3divided by 1.5

So divide 40 by 1.5

answer is 26.7

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Calculate the number of moles in a 14.5 gram sample of C4H10.

cricket20 [7]

Moles= mass divided by molar mass
Molar mass= 12.01(4) + 1.01(10)
= 58.14g/mol

Moles=14.5g / 58.14g/mol
=0.249

Therefore there are approx 0.249 moles in a 14.5g sample of C4H10

6 0

2 years ago

What mass of glucose would you need (in g) to have 0.8 mol, given that the molar mass of glucose is 180 g mol-1?

Verizon [17]

<h3>Answer: 144 g</h3>

Explanation:

Mass of glucose = moles × molar mass

∴ Mass of glucose = 0.8 mol × 180 g mol⁻¹

= 144 g

∴ the mass of glucose you need to have 0.8 mol of glucose = 144 g

5 0

2 years ago

Calculate the standard enthalpy change for the reaction at 25 ∘ C. Standard enthalpy of formation values can be found in this li

Anastasy [175]

Answer:

-179.06 kJ

Explanation:

Let's consider the following balanced reaction.

HCl(g) + NaOH(s) ⟶ NaCl(s) + H₂O(l)

We can calculate the standard enthalpy change for the reaction (ΔH°r) using the following expression.

ΔH°r = 1 mol × ΔH°f(NaCl(s)) + 1 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(HCl(g)) - 1 mol × ΔH°f(NaOH(s))

ΔH°r = 1 mol × (-411.15 kJ/mol) + 1 mol × (-285.83 kJ/mol) - 1 mol × (-92.31 kJ/mol) - 1 mol × (-425.61 kJ/mol)

ΔH°r = -179.06 kJ

7 0

3 years ago

if the density of a bar of gold is 19.3g/cm^3and you cut it into four pieces , what is its density of each piece of gold

AlladinOne [14]

Density is an intrinsic property, so it is independent of the amount of substance present: one gold coin would have the same density as a solid gold boulder.

So if the density of gold is 19.3 g/cm³, the density of a bar of gold and the pieces into which the bar is cut would all be 19.3 g/cm³.

4 0

3 years ago

Which is a saturated solution?

ser-zykov [4K]

Answer:

C）52g KCl in 100g water at 80°C

Explanation:

A saturated solution is one that contains as much solute as it can dissolve in the presence of excess solute at that particular temperature.

A solutibility curve is a graph that shows the variability with temperature of the solubility of a solute in a given solvent. A solutibility curve can provide information of whether a solution formed frommthe solute and solvent are saturated or not at a given temperature.

From the solubility curve in the attachment below:

A) A saturated solution of NH₄Cl will contain about 52 g solute per 100 g sat 50 °C. Thus, a solution of 40 g NH₄Cl in 100 g water at 50 °C is an unsaturated solution.

B) A saturated solution of SO₂ at 10°C will contain about 70 g of solute in 100 g of water. Thus a solution of 2g SO₂ in 100g water at 10°C is an unsaturated solution.

C) A saturated solution of KCl at 80 °C will contain about 52 g of solute in 100 g of water. Thus, a solution of 52g KCl in 100g water at 80°C is a saturated solution.

D) A saturated solution of Kl at 20 °C will contain about 145 g of solute in 100 g of water. Thus, a solution of 120g KI in 100g water at 20°C is an unsaturated solution.

7 0

2 years ago