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choli [55]
3 years ago
6

What does it mean when your teacher wants you to round 143 to two significant figures

Chemistry
1 answer:
zhenek [66]3 years ago
5 0

Answer:The answer is 3...I think

Explanation:

143

Sig Figs

3

Decimals

0

Scientific Notation

1.43 × 102

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Helpppppppppp!!!!!!!!!​
professor190 [17]

Answer:

a

Explanation:

the solution is extremely acidic and will dissolve the zinc rod

3 0
3 years ago
The chemical formula for aluminum hydroxide is Al(Oh)3. How many hydrogen atoms are present in 1 molecule here?
grandymaker [24]
There are three molecules of hydrogen.
5 0
4 years ago
Consider the following Reaction.
jeyben [28]

Hey there!:

Molar mass of Mg(OH)2 = 58.33 g/mol


number of moles Mg(OH)2 :

moles of Mg(OH)2 = 30.6 / 58.33 =>  0.5246 moles

Molar mass of H3PO4 =  97.99 g/mol

number of moles H3PO4:

moles of Mg(OH)2 = 63.6 / 97.99 => 0.649 moles

Balanced chemical equation is:


3 Mg(OH)2 + 2 H3PO4 --->  Mg3(PO4)2 + 6 H2O


3 mol of Mg(OH)2 reacts with 2 mol of H3PO4  ,for 0.5246 moles of Mg(OH)2, 0.3498 moles of H3PO4 is required , but we have 0.649 moles of H3PO4, so, Mg(OH)2 is limiting reagent !

Now , we will use Mg(OH)2 in further calculation  .

Molar mass of Mg3(PO4)2 = 262.87 g/mol

According to balanced equation  :

mol of Mg3(PO4)2 formed = (1/3)* moles of Mg(OH)2


= (1/3)*0.5246


= 0.1749 moles of Mg3(PO4)2

use :

mass of Mg3(PO4)2 = number of mol * molar mass


= 0.1749 *  262.87

= 46 g of Mg3(PO4)2

Therefore:

% yield = actual mass * 100 / theoretical mass

% = 34.7 * 100 / 46

% = 3470 / 46

= 75.5%


Hope that helps!




3 0
3 years ago
Which choice is an example of an endothermic process?
77julia77 [94]

Answer: conversion of ice to steam

Explanation: Endothermic process is one in which energy is absorbed by the system.

Conversion of ice to steam is change of solid phase to gaseous phase, thus energy is required to break the strong inter molecular forces of attraction in solids to convert it into gaseous phase.

Conversion of steam to ice, conversion of steam to water  and conversion of water to ice releases energy and are examples of exothermic processes.

7 0
3 years ago
Help please and thank you for who ever
Korolek [52]

Answer:the first one

Explanation:

7 0
2 years ago
Read 2 more answers
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