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maw [93]
3 years ago
11

For the most effective hot pack, should the Temperature change be positive or negative ?

Chemistry
1 answer:
bazaltina [42]3 years ago
3 0

Answer:

Positive

Explanation:

For the most effective hot pack, the temperature change should be <u>positive</u>.

<em>Hot packs are generally utilized for their heat-producing abilities. Hence, the reactions leading to the activation of hot packs are usually exothermic, that is, heat energy generating. In other words, positive or increased temperatures must be generated when hot packs are activated.</em>

This is unlike cold packs which are utilized for the cold-generating abilities. Reactions leading to their activations must be endothermic, that is, heat-absorbing.

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What is the likely impact of water's high specific heat on life on Earth? (3 points)
statuscvo [17]

Answer:

Marine life is least affected by the temperature fluctuations of the atmosphere.

Explanation:

The high specific heat capacity of water means that it takes much more energy to raise the temperatures of water by one (1) degree than land. This means that on a hot sunny day, land temperatures would increase dramatically while ocean temperatures would only rise slightly. Conversely,  at night, the land cools rapidly while oceans cool slowly hence the temperatures drop slightly.

7 0
3 years ago
Which of the following is not an external force that acts on rocks in the rock cycle? A) wind B) pressure C) ice D) water
miss Akunina [59]
Wind isn’t an external force that acts in the rock cycle.
4 0
4 years ago
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What is the percent composition of dinotrogen pentoxide? With work shown please
iris [78.8K]

Answer:

%N = 25.94%

%O = 74.06%

Explanation:

Step 1: Calculate the mass of nitrogen in 1 mole of N₂O₅

We will multiply the molar mass of N by the number of N atoms in the formula of N₂O₅.

m(N): 2 × 14.01 g = 28.02 g

Step 2: Calculate the mass of oxygen in 1 mole of N₂O₅

We will multiply the molar mass of O by the number of O atoms in the formula of N₂O₅.

m(O): 5 × 16.00 g = 80.00 g

Step 3: Calculate the mass of 1 mole of N₂O₅

We will sum the masses of N and O.

m(N₂O₅) = m(N) + m(O) = 28.02 g + 80.00 g = 108.02 g

Step 4: Calculate the percent composition  of N₂O₅

We will use the following expression.

%Element = m(Element)/m(Compound) × 100%

%N = m(N)/m(N₂O₅) × 100% = 28.02 g/108.02 g × 100% = 25.94%

%O = m(O)/m(N₂O₅) × 100% = 80.00 g/108.02 g × 100% = 74.06%

7 0
3 years ago
4. How many grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid in this
Volgvan

From the reactions, 1.04 g of H2 and 7.995 g of aluminum phosphate is produced.

<h3>What is stoichiometry?</h3>

The term stoichiometry has to do with the amount of substances that participates in a reaction.

For reaction 1;

Mg + 2HCl → MgCl₂ + H₂

Number of moles of Mg reacted =  12.5 g/24g/mol = 0.52 moles

If 1 mole of Mg produced 1 mole of H2

0.52 moles produces 0.52 moles of H2

Mass of H2 =  0.52 moles * 2 g/mol = 1.04 g

For reaction 2;

2Li3PO4 + Al2(SO4)3 → 3Li2SO4 + 2AIPO4

Number of moles of lithium phosphate =  7.5 g/116 g/mol = 0.065 moles

2 moles of Li3PO4 produced 2 moles of AIPO4

0.065 moles of  Li3PO4 produced 0.065 moles of AIPO4

Mass of AIPO4  = 0.065 moles  * 123 g/mol = 7.995 g

Learn more about stoichiometry:brainly.com/question/9743981

#SPJ1

8 0
2 years ago
How many moles of hydrogen are needed to produce 13.78 mol of ethane?
mamaluj [8]
Ethane is an alkane. Methane is also an alkane and is considered to be the simplest alkane. The difference is ethane has only 2 carbon. That carbon has 6 hydrogen attached to it. So what we do is we multiply the moles of ethane by the number of hydrogen (by dimension analysis) resulting to 82.68 moles H.
4 0
4 years ago
Read 2 more answers
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