CHEMISTRY HIGH SCHOOL

How many joules are needed to warm 45.0 grams of water from 30.0 degrees C to 75.0 degrees C?

Answers

Answer 1
Answer:

Answer : The amount of heat needed are, 8464.5 J

Explanation :

Formula used :

q=m* c* (T_(final)-T_(initial))

where,

q = heat gained = ?

m = mass of water = 45.0 g

c = specific heat of water = 4.18J/g^oC

T_(final) = final temperature = 75.0^oC

T_(initial) = initial temperature = 30.0^oC

Now put all the given values in the above formula, we get:

q=45.0g* 4.18J/g^oC* (75.0-30.0)^oC

q=8464.5J

Thus, the amount of heat needed are, 8464.5 J
Answer 2
Answer: q=m x Cp x ∆T

m is the mass of the water, Cp is the specific heat of water and ∆T is the change in temperature of the water (final-initial temperature). q is the energy involved in the reaction, measured in joules. 

q=(45.0) x (4.184 Jg^-1/°C^-1) x (45°C)
q=8472.6 Joules

Related Questions

Prior to the World Wide Web, computer users could get information only in the form of
In the important industrial process for producing ammonia (the Haber Process), the overall reaction is:N2(g) + 3H2(g) 2NH3(g) + 100.4 kJ A yield of NH3 of approximately 98% can be obtained at 200°C and 1,000 atmospheres of pressure. How many grams of Ny must react to form 1.7 grams of ammonia, NH3? 0.052 g 1.49 0.00589 2.8 g
Antacids work to relieve stomach acids because of which of the following types of reactions? A) decomposition B) double-displacement C) synthesis D) single-displacement
Why are some elements more reactive than others?
An element has an atomic number of 30. How many protons and electrons are in a neutral atom of the element? A. 30 protons, 30 electrons B. 15 protons, 15 electrons C. 60 protons, 30 electrons D. 30 protons, 0 electrons

Describe what happens to a hydrogen bond between two water molecules

Answers

Explanation:

Hydrogen atoms of one water molecule are attracted towards the oxygen atom of a neighboring water molecule can be termed as an intramolecular bond.

Generally, the oxygen atom is partially negatively charged, and the hydrogen atom is partially positively charged, so an arttraction occurs which forms this hydrogen bond. The attraction of the O-H bonding electrons towards the oxygen atom leaves a deficiency on the far side of the hydrogen atom relative to the oxygen atom. The result is that the attractive force between the O-H hydrogen and the O-atom of a nearby water molecule is strong.

What is a balanced equation for the neutralization of these two compounds? HCl
Ca(OH)2

Answers

In order to balance this, you have to count each element where the elements in the reactants side and the product side should have equal number of molecules. The balanced reaction is as follows:


2HCl + Ca(OH)2 = CaCl2 + 2H2O

In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water. What is the independent variable?a) the amount of water
b) the metals strips
c) amount of rust
d) hydrochloric acid

Answers

Answer:

b) the metals strips

Explanation:

In an experimental design, an independent variable is a variable that is changed or manipulated in a series of experiments. An independent variable is not dependent on any other variable in the experiment. The hypothesis for this experiment is stated to be: "If the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur. The independent variable relates to the type of metal wrapping strip, and the dependent variables are the amount of rusting and color of the water.

What is the atomic mass of one mole of O?

Answers

Oxygen's atomic weight is 16.00 amu. 1 mole of oxygen is 6.02 x 10^23 atoms of oxygen 1 amu = 1.661 x 10^-24g. I hope this helps you. The correct answer for this question is "1.661 x 10^-24g".

An atom that has 13 protons and 15 neutrons is an isotope of the element? How can I count it?

Answers

it's simple.
the number of protons in an atom never changes. And also, the no of protons is its atomic number.if you look up the periodic table, you will find a number on the top - left corner of each of the boxes. This is the atomic number.No 2 same elements on the periodic table have the same atomic number. So, all you have to do is search for a box that has the number 13 on it.

and by the way ... the element which you're searching for is Aluminium

What is the oxidation number of Mn in KMnO₄? a. -7
b. -3
c. 0
d. +3
e. +7

Answers

I think the answer is e? That's if o is -2 if not it will be a
Other Questions
During which step in the Can Crush Lab did the air pressure outside the can become greater than the pressure inside the can?. . A.The can was filled nearly to the top with water.. B.The can was placed on the hot stove burner for several minutes.. C.The can was removed from the hot oven burner.. D.The can was placed upside-down in the water-filled pan.
One way to slow down global climate change is toА use less nonrenewable resources. B use more nonrenewable resources. с drive cars that only burn fossil fuels. D use less dangerous ways to find oil.
What is atomic mass measured in on the periodic table?
Chemical reactions can be detected by the formation of a gas. a. Trueb. False