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3 years ago

Suppose that a new element has been made. Chemical tests

1 answer:

8 0

Chemical tests show that it is an alkaline earth metal. (a) The family of alkaline earth metals lies in group II of the periodic table indicating that each member of this family has 2 valence electrons. This therefore implies that the new element must also have only 2 electrons in its outermost orbit.

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The decomposition of nitryl chloride is described by the following chemical equation: 2NO2C1(g) → 2NO2 (g)-C12 (g) Suppose a two

Gnoma [55]

Answer:

Second reaction

NO2 + F -------> NO2F

Rate of reaction:

k1 [NO2] [F2]

Explanation:

NO2 + F2 -----> NO2F + F slow step1

NO2 + F -------> NO2F fast. Step 2

Since the first step is the slowest step, it is the rate determining step of the reaction

Hence:

rate = k1 [NO2] [F2]

6 0

3 years ago

What is the mass of 23 moles of lithium atoms

allochka39001 [22]

Take 23mols and multiply it by the atomic mass of Li:

23mol * 6.94g/mol = 159.62g

5 0

3 years ago

A space probe on the surface of mars sends a radio signal back to earth,a distance of 7.19 ×10⁷ km. Radio travel at the speed of

lys-0071 [83]

Answer:

240 seconds

Explanation:

Data Given:

Distance Radio travel to earth = 7.19 ×10⁷ km

Speed of this radio signal = 3.00 ×10⁸ m/s

Solution:

First convert Km to m

1 km = 1000 m

7.19 ×10⁷ km = 7.19 ×10⁷ x 1000 = 7.19 × 10¹⁰m

Formula used to calculate time

Speed (S) = distance (d) / time (t)

rearrange above equation for time

time (t) = distance (d) / Speed (S) . . . . . . . . .(1)

Put values in equation 1

time (t) = 7.19 × 10¹⁰/ 3.00 ×10⁸ m/s

time (t) = 240 s

So 240 seconds it take for the signal to reach the earth

6 0

4 years ago

Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: 28.03%

nlexa [21]

Answer: The empirical and molecular formula of chrysotile is $Mg_3Si_2H_3O_4$ and $Mg_6Si_4H_6O_{16}$

Explanation:

We are given:

Percentage of Mg = 28.03 %

Percentage of Si = 21.60 %

Percentage of H = 1.16 %

Percentage of O = 49.21 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of Mg = 28.03 g

Mass of Si = 21.60 g

Mass of H = 1.16 g

Mass of O = 49.21 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Magnesium = $\frac{\text{Given mass of Magnesium}}{\text{Molar mass of Magnesium}}=\frac{28.03g}{24g/mole}=1.17moles$

Moles of Silicon = $\frac{\text{Given mass of Silicon}}{\text{Molar mass of Silicon}}=\frac{21.06g}{28g/mole}=0.752moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{1.16g}{1g/mole}=1.16moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{49.21g}{16g/mole}=3.07moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.752 moles.

For Magnesium = $\frac{1.17}{0.752}=1.5$

For Silicon = $\frac{0.752}{0.752}=1$

For Hydrogen = $\frac{1.16}{0.752}=1.5$

For Oxygen = $\frac{3.07}{0.485}=4.08\approx 4$

To convert the mole ratios into whole numbers, we multiply individual mole ratios by 2

Mole ratio of Magnesium = (2 × 1.5) = 3

Mole ratio of Silicon = (2 × 1) = 2

Mole ratio of Hydrogen = (2 × 1.5) = 3

Mole ratio of Oxygen = (2 × 4) = 8

Step 3: Taking the mole ratio as their subscripts.

The ratio of Mg : Si : H : O = 3 : 2 : 3 : 8

The empirical formula for the given compound is $Mg_3Si_2H_3O_8$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 520.8 g/mol

Mass of empirical formula = [(24 × 3) + (28 × 2) + (1 × 3) + (16 × 8)] = 259 g/mol

Putting values in above equation, we get:

$n=\frac{520.8g/mol}{259g/mol}=2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$Mg_{(3\times 2)}Si_{(2\times 2)}H_{(3\times 2)}O_{(8\times 2)}=Mg_6Si_4H_6O_{16}$

Hence, the empirical and molecular formula of chrysotile is $Mg_3Si_2H_3O_4$ and $Mg_6Si_4H_6O_{16}$

5 0

4 years ago

The powder-based packet to purify water failed for a number of reasons including Select one: a. Rust b. Expense c. Sales personn

grin007 [14]

Answer:

D. Contamination

8 0

4 years ago