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9966 [12]
2 years ago
15

Which sentence describes the energy changes that occur when a chemical reaction happens?

Chemistry
1 answer:
Vladimir79 [104]2 years ago
5 0

Answer: The changes in energy that occur during a chemical reaction can be seen by examining the changes in chemical bonding. This can be used to classify reactions as exothermic or endothermic.

Explanation:

Energy changes Breaking and making bonds during a chemical reaction bonds in the reactants are broken new bonds are made in the products energy is absorbed to break bonds. Bond-breaking is an endothermic process. Energy is released when new bonds form.

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A compound has a percent composition of 15.24% sodium (molar mass = 22.99
RUDIKE [14]

The empirical formula of the compound obtained from the question given is NaBrO₃

<h3>Data obtained from the question </h3>
  • Sodium (Na) = 15.24%
  • Bromine (Br) = 52.95%
  • Oxygen (O) = 31.81%
  • Empirical formula =?

<h3>How to determine the empirical formula </h3>

The empirical formula of the compound can be obtained as illustrated below:

Divide by their molar mass

Na = 15.24 / 22.99 = 0.663

Br = 52.95 / 79.90 = 0.663

O = 31.81 / 16 = 1.988

Divide by the smallest

Na = 0.663 / 0.663 = 1

Br = 0.663 / 0.663 = 1

O = 1.988 / 0.663 = 3

Thus, the empirical formula of the compound is NaBrO₃

Learn more about empirical formula:

brainly.com/question/24297883

8 0
2 years ago
HELP PLEASE WITH 1 QUESTION.
Nata [24]
The activity series goes top to bottom, most active to least active elements, going: Li, K, Ba, Sr, Ca, Na, Mg, Mn, Zn, Fe, Cd, Co, Ni, Sn, Pb, H, Cu, Ag, Hg, Au. 

Thus, your list of metals would go from most reactive to least reactive: Li, K, Mg, Zn, Fe, Cu, Au
8 0
3 years ago
The tools shown in the diagram are used for gardening Each tool is made up
postnew [5]

Answer:

D

Explanation:

The longer handles distribute the force across a longer distance.

7 0
3 years ago
Using the solubility graph place the substances in order from most soluble (#1) to least soluble at 40°C. KNO3, NaClO3,KBr, NaCl
mestny [16]

Answer:

  • NaClO₃ > KBr > KNO₃ > NaCl.

Explanation:

The attached file contains the graph with the solubility curves for the four substances, KNO₃, NaClO₃, KBr, NaCl.

To determine the solubility of each salt at a certain temperature, you read the temperature on the horizontal axis, labeled Temperature (ºC), and move upward up to intersecting the curve of the corresponding salt. Then, move horizontally up to insersceting the vertical axis, labeled Solubility (g/100g of H₂O), to read the solubility.

The higher the reading on the vertical axis, the higher the solubility.

The red vertical line that I added is at a temperature of 40ºC.

The number in blue indicate the order in which the solubility curves are intersected at that temperature:

  • 4: NaCl: this is the lowest solubility
  • 3: KNO₃: this is the second lowest solubility
  • 2: KBr: this is the third lowest solubility
  • 1: NaClO₃: this is the highest solubility.

Thus, the rank, from most soluble to least soluble is:

  • NaClO₃ > KBr > KNO₃ > NaCl.

7 0
3 years ago
2. How do we know if a hypothesis is scientific?
antoniya [11.8K]
The hypothesis can’t be a opinion or something that has nothing to do with your work

For example;if you want to see if your toilet paper is sturdy and you say “i think it will cause the commercial says it does” (wrong) answer would have to be “i infer that the toilet paper will be sturdy because it looks more resistant than other paper I’ve seen”
8 0
3 years ago
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