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3 years ago

11

_______________ reactions transfer energy to the surroundings, usually as heat. A) Decomposition B) Endothermic C) Exothermic D)

Synthesis

2 answers:

a_sh-v [17]3 years ago

7 0

Answer: C

Explanation:

Blababa [14]3 years ago

3 0

Answer: C EXOTHERMIC

Explanation:

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Please give me two properties that glass and plastic always share

mylen [45]

Answer:

both are solids, both are somewhat pliable

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3 years ago

A chunk of tin weighing 18.5 grams and originally at 97.38 °C is dropped into an insulated cup containing 75.7 grams of water at

weqwewe [10]

Answer:

22.44°C will be the final temperature of the water.

Explanation:

Heat lost by tin will be equal to heat gained by the water

$-Q_1=Q_2$

Mass of tin = $m_1=18.5 g$

Specific heat capacity of tin = $c_1=0.21 J/g^oC$

Initial temperature of the tin = $T_1=97.38^oC$

Final temperature = $T_2$ =T

$Q_1=m_1c_1\times (T-T_1)$

Mass of water= $m_2=75.7 g$

Specific heat capacity of water= $c_2=4.184 J/g^oC$

Initial temperature of the water = $T_3=21.52^oC$

Final temperature of water = $T_2$ =T

$Q_2=m_2c_2\times (T-T_3)$

$-Q_1=Q_2$

$-(m_1c_1\times (T-T_1))=m_2c_2\times (T-T_3)$

On substituting all values:

$-(18.5 g\times 0.21 J/g^oC\times (T-97.38^oC))=75.7 g\times 4.184 J/g^oC\times (T-21.52 ^oC)$

we get, T = 22.44°C

22.44°C will be the final temperature of the water.

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4 years ago

Which statement best explains the purpose of using a mole in the measurement of matter?

oee [108]

Mole is a unit that has become the way of scientist and those who are interested in the filed to count the number of substances or atoms. Thus, the answer is letter B. It will be very impractical for them to count the atoms using the natural numbers are they are very small and very numerous.

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4 years ago

Read 2 more answers

Balance the equations

OLga [1]

Answer: a) $H_3PO_4+3NaOH\rightarrow Na_3PO_4+3H_2O$

b) $PCl_3+3H_2O\rightarrow P(OH)_3+3HCl$

c) $2Al+3H_2SO_4\rightarrow Al_2(SO_4)_3+3H_2$

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.

The balanced chemical equations are :

$H_3PO_4+3NaOH\rightarrow Na_3PO_4+3H_2O$

$PCl_3+3H_2O\rightarrow P(OH)_3+3HCl$

$2Al+3H_2SO_4\rightarrow Al_2(SO_4)_3+3H_2$

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3 years ago

How many atoms are in 131.97 liters of water vapor at STP?

olchik [2.2K]

It's D. 1.0645 × 1025

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4 years ago