What is the balanced chemical symbol equation for silicon + water?

Dissolving 5.28 g of an impure sample of calcium carbonate in hydrochloric acid produced 1.14 l of carbon dioxide at 20.0 Â°c an

kvv77 [185]

Answer:

Percentage by mass of calcium carbonate in the sample is 93.58%.

Explanation:

Assumptions:

calcium carbonate was dissolved completely and the amount of carbon dioxide released was proportional to the amount of calcium carbonate.
the sample did not contain any other compound that released or reacted with carbon dioxide.

$PV = nRT$

$n = \frac{PV}{RT}$

$P = 791 mmHg = \frac{791 mmHg}{760 mmHg} x 1 atm = 1.040789 atm.$

$R = 8.314 \frac{J}{K*mol} = 0.082 \frac{L*atm}{K*mol}$

$T = 20^{0}C + 273^{0} C = 293 K$

$n = \frac{1.040789 atm * 1.14 L}{0.082 \frac{L * atm}{K * mol} * 293 K }$

$n = 0.0493839 mol.$

given the equation of the reaction:

$CaCO_{3} + 2HCL = CaCl_{2} + CO_{2} + H_{2}O$

from assumption:

amount carbon dioxide = amount of calcium carbonate

$n(CaCO_{3} ) = n(CO_{2} )$

reacting mass ( m ) = Molar Mass ( M ) * Amount ( n )

$m(CaCO_{3} ) = n(CaCO_{3} ) * M(CaCO_{3} )$

m = 0.04938397 $mol$ * 100 $\frac{g}{mol}$ = 4.93839 $g$

percentage by mass of CaC $O_{3}$ = $\frac{mass of pure }{mass of impure}*100 = \frac{4.93839g}{5.28g}*100 = 93.5802%$ .

8 0

3 years ago

Why does sugar sink to the bottom of a tea cup?

Mandarinka [93]

Because it is more dense than the water or tea.

4 0

3 years ago

Read 2 more answers

What is a change in the arrangement of bases in a gene called?????

Jobisdone [24]

Asexual reproduction.<span>
</span>

4 0

3 years ago

Read 2 more answers

An FAS calibration curve (absorbance, y-axis vs. FAS in g/mL) gave an equation he regression line of: y-3678(x)+0.056. If an unk

mezya [45]

Answer:

FAS concentration = 1.61*10^-4M

Explanation:

Beer Lambert's law relates the absorbance (A) of a substance to its concentration (c) as:

$A = \epsilon lc----(1)$

where ε = molar absorption coefficient

l = path length

A plot of 'A' vs 'c' gives a straight line with slope = εl

In addition absorbance (A) is related to % Transmittance (%T) as:

A = 2-log%T----(2)

For the FAS solution, the corresponding calibration fit is given as:

y = 3678(x) + 0.056

This implies that the slope = εl = 3678

It is given that %T = 25.6%

$A = 2-log(25.6)=0.592$

Based on equation(1):

$c = \frac{A}{\epsilon l}=\frac{0.592}{3678}=1.61*10^{-4}M$

8 0

3 years ago

Need help asap!

Scilla [17]

Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur

2. B) $NH_3$

3. B) Fluorine

Explanation:

1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.

Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7

Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.

2. A molecular compound is usually composed of two or more nonmetal elements. Example: $NH_3$

Ionic compound is formed by the transfer of electrons from metals to non metals. Example: $Mg_3N_2$ , $AlCl_3$ and $LiBr$

3. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Here K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas $F_2$

4 0

2 years ago