Chocolate candy melting in your hand is what type of heat transfer

Help me with this question please

mash [69]

Answer:

a. Oxidising agent: Cl₂

b. Reducing agent: NaBr

c. Oxidised: NaBr

d. Reduced: Cl₂

e. Oxidation numbers before reaction: Cl= 0, Na= +1, Br= -1

f. Oxidation numbers after reaction: Cl= -1, Na= +1, Br= 0

Explanation:

Oxidising agents reduces themselves, oxidising other elements/compounds.

Reducing agents oxidise themselves, reducing other elements/compounds.

Oxidation is the loss of electrons or an increase in oxidation number.

Reduction is the gain of electrons or decrease in oxidation number.

6 0

1 year ago

The cylinder of aluminum in class was approximately 13mm in circumference and 42mm in length. What would be it's approximate mas

Roman55 [17]

Answer:

Mass, m = 1.51 grams

Explanation:

It is given that,

The circumference of Aluminium cylinder, C = 13 mm = 1.3 cm

Length of the cylinder, h = 4.2 cm

We know that the density of the Aluminium is 2.7 g/cm³

Circumference, C = 2πr

$r=\dfrac{C}{2\pi}\\\\r=\dfrac{1.3}{2\pi}\\\\r=0.206\ cm$

Density is equal to mass per unit volume.

$d=\dfrac{m}{V}$

m is mass of the cylinder

V is the volume of the cylinder

$V=\pi r^2h\\\\V=\dfrac{22}{7}\times0.206^2\times 4.2\\\\V=0.5601\ cm^3$

So,

$m=d\times V\\\\m=2.7\times 0.5601\\\\m=1.51\ g$

So, the mass of the cylinder is 1.51 grams.

5 0

3 years ago

Be sure to answer all parts. Carbon dioxide (CO2) is the gas that is mainly responsible for global warming (the greenhouse effec

Elena L [17]

Answer:

1.60x10⁶ billions of g of CO₂

Explanation:

Let's calculate the production of CO₂ by a single human in a day. The molar mass of glucose is 180.156 g/mol and CO₂ is 44.01 g/mol. By the stoichiometry of the reaction:

1 mol of C₆H₁₂O₆ -------------------------- 6 moles of CO₂

Transforming for mass multiplying the number of moles by the molar mass:

180.156 g of C₆H₁₂O₆ ----------------- 264.06 g of CO₂

4.59x10² g ---------------- x

By a simple direct three rule:

180.156x = 121203.54

x = 672.77 g of CO₂ per day per human

So, in a year, 6.50 billion of human produce:

672.77 * 365 * 6.50 billion = 1.60x10⁶ billions of g of CO₂

5 0

2 years ago

What is NaOH in science

xz_007 [3.2K]

Answer: Sodium hydroxide

7 0

3 years ago

Read 2 more answers

What is the freezing point of a solution of 498mL of water (solute) dissolved in 2.50 L of ethanol (solvent), C2H5OH? The densit

jok3333 [9.3K]

Answer:

Freezing T° of solution is -142.4°C

Explanation:

This excersise is about colligative properties, in this case freezing point depression,

ΔT = Kf . m . i

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

Kf = Cryoscopic constant

m = mol/kg (molality)

i = Number of ions dissolved.

Water is not ionic, so i = 1

Let's find out m.

We determine mass of water, by density

498ml . 1 g/mL = 498 g

We convert the mass of water to moles → 498 g . 1mol/18g = 27.6 moles

We determine mass of solvent by density

2500 mL . 0.789 g/mL = 1972.5 g

Notice, we had to convert L to mL to cancel units.

1 cm³ = 1 mL

We convert the mass from g to kg → 1972.5 g . 1kg /1000g = 1.97kg

We determine m = mol/kg → 27.6mol / 1.97kg = 13.9 m

Kf for ethanol is: 1.99 °C/m

Freezing T° for ethanol is: -114.6°C

We replace at formula: - 114.6°C - Freezing T° solution = 1.99 °C/m . 13.9 m . 1

- 114.6°C - Freezing T° solution = 27.8 °C

- Freezing T° solution = 27.8°C + 114.6°C

Freezing T° Solution = - 142.4 °C

7 0

2 years ago