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Gelneren [198K]
3 years ago
6

Hand disinfection is frequently recommended for prevention of transmission of the rhinovirus that causes the common cold. A tota

l of 212 volunteers were assigned at random to enter the hand-sanitizer group (HL+, which used the sanitizer every three hours or after handwashing) and the control group which was asked to use routine hand washing but avoid alcohol-based hand sanitizers.
Yes(infection) no(infection)
HL+ 49 67
Control 49 47
Do the data give good evidence that the above hand sanitizing practice reduced the chance of getting the common cold?
Chemistry
1 answer:
Dmitry [639]3 years ago
5 0

Answer:

No

Explanation:

AS there are more that are sick in the HL+ group than in the control group.

You might be interested in
- Explain how ionic bonds, covalent bonds, and metallic bonds each form and how.
-Dominant- [34]

Answer:  -Ionic bonds form when one atom provides electrons to another atom. Covalent Bonds: Covalent bonds form when two atom shares their valence electrons. Metallic Bonds: Metallic bonds form when a variable number of atoms share a variable number of electrons in a metal lattice.

-Covalent Bonds.

Covalent Compounds. Contain no metals and no ions. Covalent compounds contain nonmetals only.

Example:

Ionic Compounds. A metal with a non-metal. Doesn't use prefixes for naming. Name the metal and change the nonmetal ending to -ide.

Explanation: Ionic bonds form when a nonmetal and a metal exchange electrons, while covalent bonds form when electrons are shared between two nonmetals. An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions.

6 0
2 years ago
Determine the freezing point and boiling point of a solution that has 68.4 g of sucrose
Ymorist [56]

Answer:

Freezing T° of solution = - 3.72°C

Boiling T° of solution =  101.02°C

Explanation:

To solve this we apply colligative properties. Firstly, freezing point depression:

ΔT = Kf . m . i

ΔT = Freezing T° of pure solvent - Freezing T° of solution

Kf = Cryoscopic constant, for water is 1.86 °C/m

m = molality (moles of solute in 1kg of solvent)

i = Ions dissolved in solution

Our solute is sucrose, an organic compound so no ions are defined. i = 1.

Let's determine the moles: 68.4 g . 1mol/ 342g = 0.2 moles

molality = 0.2 mol / 0.1kg of water = 2 m

We replace data: ΔT = 1.86°C/m . 2m . 1

Freezing T° of solution = - 3.72°C

Now, we apply elevation of boiling point: ΔT = Kb . m . i

ΔT = Boiling T° of solution - Boiling T° of  pure solvent

Kf = Ebulloscopic constant, for water is 0.512 °C/m

We replace:

Boiling T° of solution - Boiling T° of pure solvent = 0.512 °C/m . 2 . 1

Boiling T° of solution = 0.512 °C/m . 2 . 1 + 100°C → 101.02°C

6 0
2 years ago
Draw the structure of the bromohydrin formed when (Z)-3-hexene reacts with Br2/H2O. Use the wedge/hash bond tools to indicate st
Ipatiy [6.2K]

Answer:

(3R,4R)-4-bromohexan-3-ol

Explanation:

In this case, we have  reaction called <u>halohydrin formation</u>. This is a <u>markovnikov reaction</u> with <u>anti configuration</u>. Therefore the halogen in this case "Br" and the "OH" must have <u>different configurations</u>. Additionally, in this molecule both carbons have the <u>same substitution</u>, so the "OH" can go in any carbon.

Finally, in the product we will have <u>chiral carbons</u>, so we have to find the absolute configuration for each carbon. On carbon 3 we will have an "R" configuration on carbon 4 we will have also an "R" configuration. (See figure 1)

I hope it helps!

5 0
3 years ago
1500 millimeters to km
gizmo_the_mogwai [7]
0.0015 kilometers is for sure the answer!
4 0
3 years ago
Marie discovers boxes of elements in a storage room. The boxes do not say which elements they contain, but they do have informat
elena-s [515]

The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.

7 0
3 years ago
Read 2 more answers
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