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3 years ago

Looking at the periodic table, which of these elements has the smallest atomic radius?

1 answer:

8 0

Helium
Remember: electron filling of atomic shell ...
The element which have electron in the lowest quantum shell will have the smallest atomic radius\

He:1s1 (Helium)

H:1s2 (hydrogen)

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The wax of a burning candle is a fuel that combines with oxygen in the air. As the fuel is consumed, what happens to most of the

Molodets [167]

D. It is released as heat and light.

7 0

4 years ago

Read 2 more answers

A rigid tank contains 0.66 mol of oxygen (O2). Find the mass of oxygen that must be withdrawn from the tank to lower the pressur

dsp73

Answer:

12.8 g of $O_{2}$ must be withdrawn from tank

Explanation:

Let's assume $O_{2}$ gas inside tank behaves ideally.

According to ideal gas equation- $PV=nRT$

where P is pressure of $O_{2}$ , V is volume of $O_{2}$ , n is number of moles of $O_{2}$ , R is gas constant and T is temperature in kelvin scale.

We can also write, $\frac{V}{RT}=\frac{n}{P}$

Here V, T and R are constants.

So, $\frac{n}{P}$ ratio will also be constant before and after removal of $O_{2}$ from tank

Hence, $\frac{n_{before}}{P_{before}}=\frac{n_{after}}{P_{after}}$

Here, $\frac{n_{before}}{P_{before}}=\frac{0.66mol}{43atm}$ and $P_{after}=17atm$

So, $n_{after}=\frac{n_{before}}{P_{before}}\times P_{after}=\frac{0.66mol}{43atm}\times 17atm=0.26mol$

So, moles of $O_{2}$ must be withdrawn = (0.66 - 0.26) mol = 0.40 mol

Molar mass of $O_{2}$ = 32 g/mol

So, mass of $O_{2}$ must be withdrawn = $(32\times 0.40)g=12.8g$

7 0

3 years ago

The following shows the precipitation reaction of barium chloride (BaCl₂) and sodium hydroxide (NaOH):

Nadya [2.5K]

Answer:

The answer to your question is:

a) BaCl2

b) 0.8208 g

c) yield = 85.3 %

Explanation:

BaCl₂(aq) + NaOH(aq) ----> Ba(OH)₂(s) + 2NaCl(aq)

Data

a) 1 g of BaCl₂

1 g of NaOH

MW BaCl2 = 137 + (35.5x2) = 208 g

MW NaOH = 23 + 16 + 1 = 40 g

208 g of BaCl2 ------------- 1 mol

1 g of BaCl2 ------------- x

x = ( 1 x 1) / 208 = 0.0048 mol of BaCl2

40 g of NaOH ------------ 1 mol

1 g of NaOH ------------ x

x = (1 x 1) / 40

x = 0.025 mol of NaOH

The ratio BaCl2 to NaOH is 1:1 (in the equation)

But experimentally we have 0.0048 : 0.025, so the limiting reactant is BaCl2, because is in lower concentration.

1 mol of BaCl2 -------------- 1 mol of Ba(OH)2

0.0048 mol --------------- x

x = (0.0048 x 1) / 1

x = 0.0048 mol of Ba(OH)2

MW Ba(OH)2 = 137 + 32 + 2 = 171 g

171 g of Ba(OH)2 -------------------- 1 mol

x -------------------- 0.0048 mol

x = (0.0048 x 171) / 1

x = 0.8208 g

c)Data

Ba(OH)2 = 0.700 g

% yield = 0.700 / 0.8208 x 100

% yield = 85.3

Sorry, i don't understand this question

6 0

3 years ago

Why are the densities of corn syrup and gasoline expressed as a range of values

balu736 [363]

<span> because gasoline changes volume as a function of temperature or because there are different grades of gasoline or because the values are given in different units of measure .</span>

7 0

3 years ago

Which substance has the highest melting point? Select one: a. sugar b. Oxygen c. Diamond

Westkost [7]

Answer:

Diamonds

Explanation:

The melting point of sugar is 186C

The melting point of oxygen is -218C

The melting point of diamonds are 4078C

Therefore diamonds have the highest melting point.

You can also think of their structures, as diamonds have a covalent network structure, meaning they are really strong and have a high melting point

Oxygen has a covalent molecular structure

Sugar has a much weaker covalent network structure

5 0

3 years ago