27. Lithium carbonate and calcium nitrate solutions are mixed. write the complete and NET ionic equations.

the specific heat capacity of water is 1 cal/gc how much heat in calories is released when 25.7 of water is cooled from 85 to 49

liraira [26]

Answer:

The amount of heat that is released is -925.2 cal

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is the amount of heat that a body can receive or release without affecting its molecular structure, that is, it does not change the state (solid, liquid, gaseous). In other words, sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state.

The equation that allows to calculate heat exchanges is:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.

In this case:

c= 1 $\frac{cal}{g*C}$
m= 25.7 g
ΔT= Tfinal - Tinitial= 49 °C - 85 °C= -36 °C

Replacing:

Q= 1 $\frac{cal}{g*C}$ *25.7 g* (-36 C)

Solving:

Q= -925.2 cal

<u><em>The amount of heat that is released is -925.2 cal</em></u>

8 0

3 years ago

A certain molecular compound has a solubility in hexane of at . Calculate the mass of that's dissolved in of a saturated solutio

Alex777 [14]

The question is incomplete. The complete question is:

A certain molecular compound M has a solubility in acetone of 0.737g/mL at 10.°C .Calculate the mass of M that's dissolved in 9.0 L of a saturated solution of M in acetone at this temperature.

Be sure your answer has the correct unit symbol and number of significant digits.

Answer: 6633 g of M is dissolved in 9.0 L of saturated solution in hexane at this temperature.

Explanation:

Given : 0.737g of solute is present in 1ml of solution

i.e 1ml of solution contains = 0.737 g of solute

Thus 9L or 9000ml of solution contains= $\frac{0.737g}{1ml}\times 9000ml=6633g$

Thus 6633 g of M is dissolved in 9.0 L of saturated solution in hexane at this temperature.

3 0

4 years ago

Which of the following statements about neutrons is true

Setler [38]

The answer is A: neutrons help make an atom more stable.

Neutrons do not have a charge, and they weigh about the same as a proton. Neutrons make an atom more stable because they hold the protons together. Without neutrons, the protons would separate from each other.

The answer is A: neutrons help make an atom more stable.

4 0

4 years ago

A sample of raw mining ore contains a hydrated salt called copper sulfate tetrahydrate, CuSO4.4H2O, along with other impurities.

julsineya [31]

Answer:

88.5 % of the raw ore is CuSO4*4H2O

Explanation:

Step 1: Data given

Mass of the ore = 10.854 grams

Mass of water = 2.994 grams

Step 2: Calculate moles H2O

Moles H2O = mass H2O / molar mass H2O

Moles H2O = 2.994 grams / 18.02 g/mol

Moles H2O = 0.166 moles

Step 3: Calculate moles CuSO4*4H2O

For 1 mol CuSO4*4H2O we have 4 moles H2O

For 0.166 moles H2O we have 0.166/4 = 0.0415 moles CuSO4*4H2O

Step 4: Calculate mass CuSO4*4H2O

Mass CuSO4*4H2O = moles * molar mass

Mass CusO4*4H2O = 0.0415 moles * 231.67 g/mol

Mass CuSO4*4H2O = 9.61 grams

Step 5: Calculate mass % of CuSO4*4H2O

Mass % = (9.61 grams / 10.854 grams )*100 %

Mass % = 88.5 %

88.5 % of the raw ore is CuSO4*4H2O

4 0

4 years ago

Specifically, what do we mean when we say that a scientific hypothesis must be testable?

castortr0y [4]

Answer:

Explanation:

Specifically, what do we mean when we say that a scientific hypothesis must be testable? It must be able to be proven wrong. ... A scientific fact is something that observers can observe and agree to be true. A hypothesis is an educated guess that answers a question.

3 0

4 years ago

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27. Lithium carbonate and calcium nitrate solutions are mixed. write the complete and NET ionic equations.​

27. Lithium carbonate and calcium nitrate solutions are mixed. write the complete and NET ionic equations.