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3 years ago

How many aluminum atoms are in 2.58 grams of aluminum

Chemistry

1 answer:

Ket [755]3 years ago

6 0

Answer:

5.75x10^22 atoms

Explanation:

From a clear understanding of Avogadro's hypothesis, we discovered that 1mole of any substance contains 6.02x10^23 atoms. This implies that 1mole of Al also contains 6.02x10^23 atoms.

1mole of Al = 27g

If 27g of Al contains 6.02x10^23 atoms, then 2.58g of Al will contain = (2.58 x 6.02x10^23)/27 = 5.75x10^22 atoms

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H2SO4 + 2 KOH --> K2SO4 + 2 H2O

alisha [4.7K]

Double replacement because H and K are both switching

8 0

3 years ago

A 0.105 L sample of an unknown HNO 3 solution required 35.7 mL of 0.250 M Ba ( OH ) 2 for complete neutralization. What is the c

oksano4ka [1.4K]

Answer: 0.17M

Explanation:

The equation for the reaction is :

2HNO3 + Ba(OH)2 —> Ba(NO3)2 + 2H2O

From the balanced equation, we obtain :

nA = mole of acid = 2

nB = mole of the base = 1

From the question, we obtain:

Va = Vol. Of acid = 0.105L

Ma = conc. Of acid =?

Vb = Vol of base = 35.7 mL = 0.0357L

Mb = conc. of base = 0.25M.

We solve for the conc. of the acid using:

MaVa / Mb Vb = nA / nB

(Ma x 0.105) / (0.25x0.0357) = 2

Cross multiply to express in linear form. We have:

Ma x 0.105 = 0.25 x 0.0357 x 2

Divide both side by 0.105. We have

Ma = (0.25 x 0.0357 x 2) / 0.105

Ma = 0.17M

Therefore the concentration of the acid(HNO3) is 0.17M

3 0

2 years ago

How many moles are in 22 grams of neon?

11111nata11111 [884]

Answer:

0.9911 mol

Explanation:

7 0

3 years ago

In a given column of the periodic table the elements have _____.

kakasveta [241]

Answer:

a. similar properties

Explanation:

In a given column of the periodic table, the elements have similar properties.

A column on the periodic table is known as a group or family. The group is a vertical arrangement of elements on the periodic table.

Elements in the same group have the same number of valence electrons after their group number.

For example, all the elements in group 1 have one valence electron. Those in group 2 have 2 valence electrons.

The valence electrons of an atom determines its chemical properties. So, all elements in the same group have the same chemical properties.

6 0

3 years ago

There are two naturally occurring isotopes of boron. 10 B has a mass of 10.0129 u. 11 B has a mass of 11.0093 u. Determine the a

Vanyuwa [196]

<h2>Natural Abundance for 10B is 19.60%</h2>

Explanation:

The natural isotopic abundance of 10B is 19.60%.

The natural isotopic abundance of 11B is 80.40%.

The isotopic masses of boron are 10.0129 u and 11.009 u respectively.

For calculation of abundance of both the isotopes -

Supposing it was 50/50, the average mass would be 10.5, so to increase the mass we need a more percentage of 11.

Determining it as an equation -

10x + 11y= 10.8

x+y=1 (ratio)

10x + 10y = 10

By taking the denominator away from the numerator

we get;

y = 0.8

x + y = 1

∴ x = 0.2

To get percentages we need to multiply it by 100

So, the calculated abundance is 80% for 11 B and 20% 10 B.

5 0

3 years ago