Answer:
Volume of the sulfuric acid (25cm³), same mass of each metal (1g)
Explanation:
In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.
In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.
1 N₂ + 3 H₂ = 2 NH₃
Mole ratio <span> of hydrogen to ammonia :
3 moles H</span>₂ : 2 moles NH₃ or 3 : 2
hope this helps!
Answer:
compound machine
Explanation:
A machine made of two or more simple machines is known as a compound machine.
They are usually derived by coupling or joining simple appliances together to make one compound device.
- This is done to increase mechanical advantage and to perform different tasks.
- Common examples are bicycles, shovels etc.