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3 years ago

If you pump air into cycle tyre a slight warming effect is noticed at valve stem why

1 answer:

6 0

As the air molecules move through the valve they have friction as they hit the walls, and its this friction that causes it to heat up.

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1. Using the balanced equation, answer the following questions:

nalin [4]

Answer:

a) 2.53 × 10²³ molecules of O₂

b) 31.90 g of KCl

Explanation:

The balance chemical equation for given decomposition reaction is as follow;

2 KClO₃ → 2 KCl + 3 O₂

Step 1: <u>Calculate Moles for given amount of KClO₃;</u>

Moles = Mass / M.Mass

Moles = 34.35 g / 122.55 g/mol

Moles = 0.280 moles of KClO₃

Step 2: <u>Find out moles of O₂ produced;</u>

According to eq,

2 moles of KClO₃ produces = 3 moles of O₂

So,

0.280 moles of KClO₃ will produce = X moles of O₂

Solving for X,

X = 0.280 mol × 3 mol / 2 mol

X = 0.42 moles of O₂

Step 3: <u>Calculate No. of Molecules of O₂ as,</u>

No. of Molecules = Moles × 6.022 × 10²³

No. of Molecules = 0.42 mol × 6.022 × 10²³ molecules/mol

No. of Molecules = 2.53 × 10²³ molecules of O₂

Step 1: <u>Calculate Moles for given amount of KClO₃;</u>

Moles = Mass / M.Mass

Moles = 52.53 g / 122.55 g/mol

Moles = 0.428 moles of KClO₃

Step 2: <u>Find out moles of KCl produced;</u>

According to eq,

2 moles of KClO₃ produces = 2 moles of KCl

So,

0.428 moles of KClO₃ will produce = X moles of KCl

Solving for X,

X = 0.428 mol × 2 mol / 2 mol

X = 0.428 moles of KCl

Step 3: <u>Calculate Mass of KCl as;</u>

Mass = Moles × M.Mass

Mass = 0.428 mol × 74.55 g/mol

Mass = 31.90 g of KCl

6 0

2 years ago

Which is the most reactive metal and why?

Gemiola [76]

Answer:

Caesium, the most reactive metal in the periodic table, reacts extremely violently – hence why it can't be demonstrated in a classroom! This can be compared to other common metals, such as iron and copper, which produce no reaction when dropped into water.

Hope this answer is right!

3 0

2 years ago

What is the specific heat of copper when heated to 221.32

Dafna1 [17]

Answer:

The specific heat of copper when heated to 221.32 (not listed form of heat measurement) is 221.32 (not listed form of heat measurement).

Explanation:

uh not really sure what else there is here, I may be missing something

5 0

2 years ago

Write a mechanism for the esterification of propanoic acid with 18O-labeled ethanol. Show clearly the fate of the 18O label. (b)

tatuchka [14]

Answer:

See explanation and images attached

Explanation:

a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.

b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.

5 0

2 years ago

How many electrons elements are present in period 2 ?

AVprozaik [17]

There are Eight elements

3 0

2 years ago

Read 2 more answers