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1 year ago

How many atoms are in 76.15 grams of fe urgently needed, will mark brainliest

Chemistry

1 answer:

Ira Lisetskai [31]1 year ago

3 0

Answer:

See below

Explanation:

From periodic table

mole weight of Fe is 55.845 gm / mole

76.15 gm / 55.845 gm/mol * 6.022 x 10^23 atoms/mole =

8.212 x 10^23 atoms ( four signif. digits)

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What is true about energy?

xeze [42]

The correct answer is option A. Energy cannot be created during an ordinary chemical reaction. There is no such thing as an ordinary chemical reaction. Energy cannot be created or destroyed this is according to the law of conservation of energy. It can only be transformed from one form to another form.

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2 years ago

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Is a situation in which a dominant allele completely masks a recessive allele for a gene.

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Complete dominance.... Hope this helps

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3 years ago

What volume of so2 is produced at 325 k and 1.35 atm when 15.0 grams of hcl reacts with excess k2so3?

vova2212 [387]

The volume of SO2 produced at 325k is calculated as below

calculate the moles of SO2 produced which is calculated as follows

write the reacting equation
K2SO3 +2 HCl = 2KCl +H2O+ SO2

find the moles of HCl used
=mass/molar mass = 15g/ 36.5 g/mol =0.411 moles

by use of mole ratio between HCl to SO2 which is 2:1 the moles of SO2 is therefore = 0.411 /2 =0.206 moles of SO2

use the idea gas equation to calculate the volume SO2
that is V=nRT/P
where n=0.206 moles
R(gas constant) = 0.082 L.atm/ mol.k
T=325 K
P=1.35 atm

V=(0.206 moles x 0.082 L.atm/mol.k x325 k)/1.35 atm = 4.07 L of SO2

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2 years ago

How many grams of solid NaOH are required to prepare a 400ml of a 5N solution? show your work!

Nuetrik [128]

Answer: The mass of solid NaOH required is 80 g

Explanation:

Equivalent weight is calculated by dividing the molecular weight by n factor. The equation used is:

$\text{Equivalent weight}=\frac{\text{Molecular weight}}{n}$

where,

n = acidity for bases = 1 (For NaOH)

Molar mass of NaOH = 40 g/mol

Putting values in above equation, we get:

$\text{Equivalent weight}=\frac{40g/mol}{1eq/mol}=40g/eq$

Normality is defined as the umber of gram equivalents dissolved per liter of the solution.

Mathematically,

$\text{Normality of solution}=\frac{\text{Number of gram equivalents} \times 1000}{\text{Volume of solution (in mL)}}$

Or,

$\text{Normality of solution}=\frac{\text{Given mass}\times 1000}{\text{Equivalent mass}\times \text{Volume of solution (in mL)}}$ ......(1)

We are given:

Given mass of NaOH = ?

Equivalent mass of NaOH = 40 g/eq

Volume of solution = 400 mL

Normality of solution = 5 eq/L

Putting values in equation 1, we get:

$5eq/L=\frac{\text{Mass of NaOH}\times 1000}{40g/eq\times 400mL}\\\\\text{Mass of NaOH}=80g$

Hence, the mass of solid NaOH required is 80 g

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3 years ago

Zinc blende, or sphalerite, can be described as having a face-centered cubic unit cell with sulfur atoms at each lattice point a

g100num [7]

Answer:

ZnS

Explanation:

1. Number of Zn atoms

4 internal atoms = 4 Zn atoms

2. Number of S atoms

8 corners × ⅛ S atom/corner + 6 faces × ½ S atom/face = 1 S atom + 3 S atoms = 4 S atoms

3. Empirical formula

The atomic ratio is

4Zn:4S = 1Zn:1S

The empirical formula is ZnS.

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3 years ago