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2 years ago

I need help please Which option is chemical change?

Chemistry

1 answer:

MrRa [10]2 years ago

8 0

Answer:

Getting coated with tarnish

Explanation:

Silver, the original substance is combining with a new substance tarnish to make a whole new chemical.

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A 151.5-g sample of a metal at 75.0°C is added to 151.5 g at 15.1°C. The temperature of the water rises to 18.7°C. Calculate the

Kryger [21]

Answer:

The specific heat capacity of the metal is 0.268 J/g°C

Explanation:

Step 1: Data given

Mass of the metal = 151.5 grams

The temperature of the metal = 75.0 °C

Temperature of water = 15.1 °C

The temperature of the water rises to 18.7°C.

The specific heat capacity of water is 4.18 J/°C*g

Step 2: Calculate the specific heat capacity of the metal

heat lost = heat gained

Q = m*c*ΔT

Qmetal = - Qwater

m(metal) * c(metal) * ΔT(metal) = m(water) * c(water) * ΔT(water)

⇒ mass of the metal = 151.5 grams

⇒ c(metal) = TO BE DETERMINED

⇒ΔT( metal) = T2 - T1 = 18.7 °C - 75.0 °C = -56.3 °C

⇒ mass of the water = 151.5 grams

⇒ c(water) = 4.184 J/g°C

⇒ ΔT(water) = 18.7° - 15.1 = 3.6 °C

151.5g * c(metal) * -56.3°C = 151.5g * 4.184 J/g°C * 3.6 °C

c(metal) = 0.268 J/g°C

The specific heat capacity of the metal is 0.268 J/g°C

5 0

3 years ago

1. A student tried to solve the following problem by selecting the tile as shown. What, if anything, did the student do wrong?

slega [8]

Answer:

B. The student chose the correct tile, but needs to flip the tile to make the units cancel

Explanation:

Based on the reaction:

2AgNO₃(aq) + Cu(s) → 2Ag(s) + Cu(NO₃)₂ (aq)

<em>2 moles of AgNO₃ react per mole of Cu producing 2 moles of Ag and 1 mole of Cu(NO₃)₂</em>

Thus, if you want to produce 6.75moles of Cu(NO₃)₂ you need:

$6.75moles of Cu(NO_3)_2 \frac{2 mol AgNO_3 }{1 mol Cu(NO_3)_2}$ = 13.50 moles of AgNO₃ are needed

Thus, if you analize the tile shown by the student:

<em>B. The student chose the correct tile, but needs to flip the tile to make the units cancel</em>

6 0

3 years ago

For a lake in Michigan, researchers have determined that largemouth bass feed on smaller fish, which in turn feed on zooplankton

allsm [11]

Answer:

the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

Explanation:

Given the data in the question;

In 2016, there was 600,000 kg of zooplankton in the lake.

In 2017, an accidental runoff of insecticide near the lake caused a 50 percent decline of the zooplankton population in the lake.

Now,

The remaining mass of zooplankton after the 50% decline will be;

⇒ 600,000 kg zooplankton × 50%

⇒ 600,000 × 50/100

⇒ 300,000 kg of zooplankton

Now, with 10 percent trophic efficiency; smaller fish directly feed on zooplankton; decline in smaller fish mass will be;

⇒ 300,000 kg × 10%

⇒ 300,000 × 10/100

⇒ 30000 kg

Finally, with 10 percent trophic efficiency, largemouth bash directly feed on smaller fish, so the expected decline in mass of largemouth bash will be;

⇒ 30000 kg × 10%

⇒ 30000 kg × 10/100

⇒ 3,000 kg

Therefore, the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

7 0

3 years ago

Each of the following names is wrong. Draw structures based on them, and correct the names:(b) 1,1,1-trimethylheptane

devlian [24]

The correct IUPAC name of 1,1,1-trimethylheptane is 2,2-dimethyloctane.

<h3>IUPAC NAME:</h3>

It is systematic way of nomenclature of organic compounds.

It is based on the position of functional groups, preference of the functional group, long or short chain of carbon, preference of double bond, single and triple bond, branching of carbon chain, etc.

The given compound is 1,1,1-trimethylheptane.

The given name is wrong according to IUPAC name because the numbering of carbon atom should be done in that way in which the carbon atom chain is largest.

Here, in this case the numbering is done from right side. Thus the largest carbon chain have 8 carbon atom.

If the numbering is done according to the question, number of carbon atom in straight chain is 7.

Thus, we concluded that the Correct IUPAC name of 1,1,1-trimethylheptane is 2,2-dimethyloctane.

learn more about Nomenclature:

brainly.com/question/14094007

#SPJ4

5 0

2 years ago

Which pair of ions can form an ionic bond with each other and why? A.Cu and Ag; They are both metal ions.B. S and O; They have l

kap26 [50]

Opposite pairs form ionic bonds, due to this the answer is D - Li and Br; They have unlike charges.

5 0

3 years ago

Read 2 more answers