Modern masonry fireplaces are based on designs first developed ____

The heaviest of the following would be 4 moles of?

KIM [24]

The answer is d.HCl hope this helps

5 0

3 years ago

An instant cold pack purchased in a pharmacy contains a packet of solid ammonium nitrate surrounded by a pouch of water. When th

gavmur [86]

Answer:

c

letra c certeza confia

8 0

3 years ago

The bond angle for methane is the angle determined by two consecutive hydrogen atoms and the central carbon atom.

snow_tiger [21]

Answer:

a. True

Explanation:

The bond angle for methane is the angle determined by two consecutive hydrogen atoms and the central carbon atom.

Methane, a tetrahedron has the structural formula:

H

|

H - C - H

|

H Methane, CH4

The bond angle is the angle between the H-C-H atoms and is 109.5degrees.

5 0

3 years ago

Rank and explain how the freezing point of 0.100 m solutions of the following ionic electrolytes compare. List from lowest freez

Elden [556K]

Answer:

The solutions are listed from the lowest freezing point to highest freezing point.

Mg₃(PO₄)₂ - AlBr₃ - BeBr₂ - KBr

Explanation:

Colligative property of freezing point, is the freezing point depression.

Formula is:

ΔT = Kf . m . i

Where ΔT = T° freezing pure solvent - T° freezing solution

Kf is the cryoscopic constant

m is molality and i is the Van't Hoff factor (number of ions, dissolved in solution)

In this case, T° freezing pure solvent is 0° because it's water, so the Kf is 1.86 °C/m, and m is 0.1 molal.

The i modifies the T° freezing solution. The four salts, are ionic compounds, so for each case:

BeBr₂ → Be²⁺ + 2Br⁻ i = 3

AlBr₃ → Al³⁺ + 3Br⁻ i = 4

Mg₃(PO₄)₂ → 3Mg²⁺ + 2PO₄⁻³ i = 5

KBr → K⁺ + Br⁻ i = 2

Solution of Mg₃(PO₄)₂ will have the lowest temperature of freezing and the solution of KBr, the highest (always lower, than 0°).

8 0

3 years ago

A molecule is known to have a molar absorptivity of 18,650 at a certain wavelength. A spectrometer is tuned to this wavelength a

iren2701 [21]

Answer:

17,932.69 g/mol is the molecular weight of the substance.

Explanation:

Using Beer-Lambert's law :

Formula used :

$A=\epsilon \times c\times l$

where,

A = absorbance of solution = 1.04

c = concentration of solution =?

l = length of the cell = 1 cm

$\epsilon$ = molar absorptivity of this solution = 18,650 $M^{-1} cm^{-1}$

Now put all the given values in the above formula, we get the molar absorptivity of this solution.

$1.04=18,650 M^{-1} cm^{-1}\times c)\times (1cm)$

c = $5.576\times 10^{-5} M$

$Concentration=\frac{\text{Mass of compound}}{\text{Molecular mass of compound}\times V}$

V = Volume of the solution in L

Molecular weight of the substance = x

V = 100 mL = 0.1 L

Mass of the substance = 100 mg = 0.1 g

$5.576\times 10^{-5} M=\frac{0.1 g}{x\times 0.1 L}$

x = 17,932.69 g/mol

17,932.69 g/mol is the molecular weight of the substance.

6 0

3 years ago

Modern masonry fireplaces are based on designs first developed _____.