8.6e: investigate how mass is conserved in chemical reactions and relate conservation of mass to the rearrangement of atoms using chemical equations, including photosynthesis.
a chemical equation for the reaction between calcium carbonate, caco₃, and hydrochloric acid, 2hcl, is shown. the masses of some of the reactants and products are given in grams.
caco₃ + 2hcl → cacl₂ + h₂o + co₂
—— 98 g 96 g 40 g 36 g
how many grams of calcium carbonate were used in the reaction?
a. 100 g
b. 36 g
c. 74 g
d. 62 g
determine if the following chemical equations are balanced or unbalanced.
ch₄ + 2o₂ → co₂ + 2h₂o
balanced or unbalanced?
h₃po₄ + koh → k₃po₄ + 3h₂o
balanced or unbalanced?
which statement best describes evidence that a chemical reaction occurs as a cake bakes?
a. the water in the cake batter is used to keep the cake moist as it bakes.
b. the cake takes the shape of the container in which it is baked.
c. the cake rises as gas bubbles form in the baking cake.
d. the water in the cake batter evaporates.
which of the following best illustrates the law of conservation of mass?
a. 3agno₃ + 2cu → cu(no₃)₂ + 2ag
b. 2agno₃ + cu → cu(no₃)₂ + 2ag
c. agno₃ + 2cu → 2cu(no₃)₂ + 2ag
8.10a: describe how energy from the sun, hydrosphere, and atmosphere interact and influence weather and climate
how does the interaction between the hydrosphere and the atmosphere contribute to the formation of a weather front?
a. water vapor from the ocean condenses directly into precipitation without affecting atmospheric conditions
b. the hydrosphere and atmosphere interact to keep the air temperature constant, preventing the formation of weather fronts
c. cool air from the atmosphere directly influences ocean currents without any impact on weather patterns or fronts.
d. evaporation from the ocean increases atmospheric humidity, which, when interacting with cooler air masses, can lead to cloud formation and precipitation along a weather front
which of the following best describes how the interaction of energy from the sun, the hydrosphere, and the atmosphere influences weather and climate?
a. the sun’s energy causes evaporation from the oceans, which increases atmospheric pressure and leads to clear, stable weather
b. solar energy heats the earth’s surface, causing differences in air pressure that drive wind patterns and influence weather systems, while the hydrosphere and atmosphere interact to distribute heat and moisture globally.
c. the sun’s energy is absorbed equally by all parts of the earth, leading to uniform weather conditions and a consistent climate.
d. energy from the sun causes direct warming of the atmosphere, while the hydrosphere has no significant impact on weather and climate

Question

8.6e: investigate how mass is conserved in chemical reactions and relate conservation of mass to the rearrangement of atoms using chemical equations, including photosynthesis.
a chemical equation for the reaction between calcium carbonate, caco₃, and hydrochloric acid, 2hcl, is shown. the masses of some of the reactants and products are given in grams.
caco₃ + 2hcl → cacl₂ + h₂o + co₂
—— 98 g   96 g   40 g  36 g
how many grams of calcium carbonate were used in the reaction?
a. 100 g
b. 36 g
c. 74 g
d. 62 g
determine if the following chemical equations are balanced or unbalanced.
ch₄ + 2o₂ → co₂ + 2h₂o
balanced or unbalanced?
h₃po₄ + koh → k₃po₄ + 3h₂o
balanced or unbalanced?
which statement best describes evidence that a chemical reaction occurs as a cake bakes?
a. the water in the cake batter is used to keep the cake moist as it bakes.
b. the cake takes the shape of the container in which it is baked.
c. the cake rises as gas bubbles form in the baking cake.
d. the water in the cake batter evaporates.
which of the following best illustrates the law of conservation of mass?
a. 3agno₃ + 2cu → cu(no₃)₂ + 2ag
b. 2agno₃ + cu → cu(no₃)₂ + 2ag
c. agno₃ + 2cu → 2cu(no₃)₂ + 2ag
8.10a: describe how energy from the sun, hydrosphere, and atmosphere interact and influence weather and climate
how does the interaction between the hydrosphere and the atmosphere contribute to the formation of a weather front?
a. water vapor from the ocean condenses directly into precipitation without affecting atmospheric conditions
b. the hydrosphere and atmosphere interact to keep the air temperature constant, preventing the formation of weather fronts
c. cool air from the atmosphere directly influences ocean currents without any impact on weather patterns or fronts.
d. evaporation from the ocean increases atmospheric humidity, which, when interacting with cooler air masses, can lead to cloud formation and precipitation along a weather front
which of the following best describes how the interaction of energy from the sun, the hydrosphere, and the atmosphere influences weather and climate?
a. the sun’s energy causes evaporation from the oceans, which increases atmospheric pressure and leads to clear, stable weather
b. solar energy heats the earth’s surface, causing differences in air pressure that drive wind patterns and influence weather systems, while the hydrosphere and atmosphere interact to distribute heat and moisture globally.
c. the sun’s energy is absorbed equally by all parts of the earth, leading to uniform weather conditions and a consistent climate.
d. energy from the sun causes direct warming of the atmosphere, while the hydrosphere has no significant impact on weather and climate

Accepted Answer

### First Sub - Question (Mass Conservation in Chemical Reactions)
#### Explanation:
##### Step 1: Recall the Law of Conservation of Mass
The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. The formula for this is $m_{reactants}=m_{products}$, where $m_{reactants}$ is the sum of the masses of all reactants and $m_{products}$ is the sum of the masses of all products.
##### Step 2: Calculate the total mass of products
The products are $CaCl_2$ (96 g), $H_2O$ (40 g), and $CO_2$ (36 g). So, $m_{products}=96 + 40+36=172$ g.
##### Step 3: Calculate the mass of $CaCO_3$
We know the mass of $HCl$ is 98 g. Let the mass of $CaCO_3$ be $x$. Then, $x + 98=m_{products}=172$. Solving for $x$, we get $x = 172 - 98 = 74$ g.
#### Answer:
$\boldsymbol{74}$ g (Option C)

### Second Sub - Question (Balancing $CH_4 + 2O_2
ightarrow CO_2+2H_2O$)
#### Explanation:
##### Step 1: Count the number of each atom on the reactant side
- For $C$: In $CH_4$, there is 1 $C$ atom.
- For $H$: In $CH_4$, there are $4$ $H$ atoms.
- For $O$: In $2O_2$, there are $2\times2 = 4$ $O$ atoms.
##### Step 2: Count the number of each atom on the product side
- For $C$: In $CO_2$, there is 1 $C$ atom.
- For $H$: In $2H_2O$, there are $2\times2=4$ $H$ atoms.
- For $O$: In $CO_2$ (2 $O$ atoms) and $2H_2O$ (2\times1 = 2 $O$ atoms), total $O$ atoms are $2 + 2=4$ $O$ atoms.
Since the number of each type of atom is the same on both sides, the equation is balanced.
#### Answer:
Balanced

### Third Sub - Question (Balancing $H_3PO_4+KOH
ightarrow K_3PO_4 + 3H_2O$)
#### Explanation:
##### Step 1: Count the number of each atom on the reactant side
- For $P$: In $H_3PO_4$, there is 1 $P$ atom.
- For $H$: In $H_3PO_4$ (3 $H$ atoms) and $KOH$ (let the number of $KOH$ be $x$, so $x$ $H$ atoms from $KOH$).
- For $O$: In $H_3PO_4$ (4 $O$ atoms) and $KOH$ ( $x$ $O$ atoms from $KOH$).
- For $K$: In $KOH$, there is $x$ $K$ atoms.
##### Step 2: Count the number of each atom on the product side
- For $P$: In $K_3PO_4$, there is 1 $P$ atom.
- For $H$: In $3H_2O$, there are $3\times2 = 6$ $H$ atoms.
- For $O$: In $K_3PO_4$ (4 $O$ atoms) and $3H_2O$ (3 $O$ atoms), total $O$ atoms are $4 + 3=7$ $O$ atoms.
- For $K$: In $K_3PO_4$, there are 3 $K$ atoms.

Now, let's balance the $K$ first. Since there are 3 $K$ atoms in the product ($K_3PO_4$), the number of $KOH$ (which provides $K$) should be 3. So $x = 3$.

Now check $H$: Reactant $H$: $3$ (from $H_3PO_4$)+$3$ (from 3 $KOH$)=$6$, which matches the product $H$ (6 from $3H_2O$).

Check $O$: Reactant $O$: $4$ (from $H_3PO_4$)+$3$ (from 3 $KOH$)=$7$, which matches the product $O$ (4 + 3 = 7).

So the equation is balanced.
#### Answer:
Balanced

### Fourth Sub - Question (Evidence of Chemical Reaction in Baking a Cake)
#### Brief Explanations:
A chemical reaction is characterized by the formation of new substances, often accompanied by changes like gas production, color change, or precipitate formation. Option A is about water keeping the cake moist (physical change). Option B is about the cake taking the shape of the container (physical change - shaping). Option C: The cake rising as gas bubbles form indicates a chemical reaction (gas production, new substances formed during baking like carbon dioxide from leavening agents reacting). Option D is about water evaporation (physical change).
#### Answer:
C. The cake rises as gas bubbles form in the baking cake.

### Fifth Sub - Question (Best Illustrates Law of Conservation of Mass)
#### Brief Explanations:
The law of conservation of mass in chemical reactions means that the number of each type of atom is the same on both sides of the equation. Let's analyze each option:
- Option A: $3AgNO_3+2Cu
ightarrow Cu(NO_3)_2 + 2Ag$ - The number of $NO_3^-$ groups: 3 on left, 1 on right. Not balanced.
- Option B: $2AgNO_3+Cu
ightarrow Cu(NO_3)_2+2Ag$ - Number of $Ag$: 2 on left, 2 on right; $Cu$: 1 on left, 1 on right; $NO_3^-$: 2 on left, 2 on right. Balanced, so it illustrates the law (same number of atoms on both sides).
- Option C: $AgNO_3 + 2Cu
ightarrow 2Cu(NO_3)_2+2Ag$ - Number of $NO_3^-$: 1 on left, 4 on right. Not balanced.
#### Answer:
B. $2AgNO_3 + Cu
ightarrow Cu(NO_3)_2+2Ag$

### Sixth Sub - Question (Hydrosphere - Atmosphere Interaction and Weather Front)
#### Brief Explanations:
A weather front forms due to the interaction of different air masses. Evaporation from the ocean increases atmospheric humidity. When this humid air (from the hydrosphere - ocean evaporation) interacts with cooler air masses (from the atmosphere), it can lead to cloud formation and precipitation along a weather front.
- Option A: Water vapor condenses directly to precipitation without affecting atmospheric conditions - incorrect, as atmospheric conditions are involved.
- Option B: Hydrosphere and atmosphere keep air temperature constant - incorrect, air temperature varies.
- Option C: Cool air from atmosphere directly influences ocean currents without impact on weather fronts - incorrect, the interaction is more complex and affects weather fronts.
- Option D: Evaporation from oceans increases atmospheric humidity, and interaction with cooler air leads to cloud formation and precipitation along a weather front - correct.
#### Answer:
D. Evaporation from the oceans increases atmospheric humidity, which, when interacting with cooler air masses, can lead to cloud formation and precipitation along a weather front

### Seventh Sub - Question (Sun - Hydrosphere - Atmosphere Interaction and Weather/Climate)
#### Brief Explanations:
The Sun's energy heats the Earth's surface, causing differences in air pressure (which drive wind patterns and weather systems). The hydrosphere (oceans, water bodies) and atmosphere interact to distribute heat and moisture globally.
- Option A: Evaporation from oceans increases atmospheric pressure and leads to clear weather - incorrect, evaporation affects humidity, not pressure in this way.
- Option B: Solar energy heats the Earth's surface, causing air pressure differences (driving wind), and hydrosphere - atmosphere interact to distribute heat and moisture globally - correct.
- Option C: Sun's energy is absorbed equally by all parts of the Earth - incorrect, it's absorbed unevenly (more at equator, less at poles), leading to different weather.
- Option D: Hydrosphere has no significant impact on weather and climate - incorrect, hydrosphere (oceans, etc.) plays a major role in heat and moisture distribution.
#### Answer:
B. Solar energy heats the Earth's surface, causing differences in air pressure that drive wind patterns and influence weather systems, while the hydrosphere and atmosphere interact to distribute heat and moisture globally.

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

First Sub - Question (Mass Conservation in Chemical Reactions)

Step 1: Recall the Law of Conservation of Mass

Step 2: Calculate the total mass of products

Step 3: Calculate the mass of \(CaCO_3\)

Step 1: Count the number of each atom on the reactant side

Step 2: Count the number of each atom on the product side

Step 1: Count the number of each atom on the reactant side

Step 2: Count the number of each atom on the product side

Answer:

Second Sub - Question (Balancing \(CH_4 + 2O_2